import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.PriorityQueue;
import java.io.BufferedWriter;
import java.util.InputMismatchException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.AbstractCollection;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.util.Collections;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author ilyakor
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        TaskE solver = new TaskE();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskE {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            int n = in.nextInt();
            int m = in.nextInt();
            ArrayList<ii> entries = new ArrayList<>();
            for (int i = 0; i < n; ++i) {
                entries.add(new ii(in.nextInt(), i));
            }

            SegmentTreeFastIntervalAddSum tree = new SegmentTreeFastIntervalAddSum(1 << 18);
            for (ii entry : entries) if (entry.first == 1) tree.set(entry.second + 1, 1);

            Collections.shuffle(entries);
            Collections.sort(entries);
            PriorityQueue<TaskE.Query> qu = new PriorityQueue<>();
            long[] ans = new long[m];
            for (int i = 0; i < m; ++i) {
                TaskE.Query q = new TaskE.Query(in.nextInt() - 1, in.nextInt() - 1);
                q.ind = i;
                q.sum = tree.querySum(q.l + 1, q.r + 1);
                if (q.sum == 0) {
                    ans[i] = 1;
                } else {
                    qu.add(q);
                }
            }


            for (ii entry : entries) {
                int x = entry.first, ind = entry.second;
                if (x <= 1) continue;
                while (!qu.isEmpty() && qu.peek().sum < x - 1) {
                    TaskE.Query q = qu.poll();
                    q.sum = tree.querySum(q.l + 1, q.r + 1);
                    if (q.sum >= x - 1) {
                        qu.add(q);
                    } else {
                        ans[q.ind] = q.sum + 1;
                    }
                }
                tree.set(ind + 1, x);
            }
            while (!qu.isEmpty()) {
                TaskE.Query q = qu.poll();
                q.sum = tree.querySum(q.l + 1, q.r + 1);
                ans[q.ind] = q.sum + 1;
            }
            for (int i = 0; i < m; ++i)
                out.printLine(ans[i]);
        }

        static class Query implements Comparable<TaskE.Query> {
            int l;
            int r;
            int ind;
            long sum;

            public Query(int l, int r) {
                if (l > r) {
                    int t = l;
                    l = r;
                    r = t;
                }
                this.l = l;
                this.r = r;
                sum = 0;
            }


            public int compareTo(TaskE.Query o) {
                return Long.compare(sum, o.sum);
            }

        }

    }

    static class ii implements Comparable<ii> {
        public int first;
        public int second;

        public ii() {
        }

        public ii(int first, int second) {
            this.first = first;
            this.second = second;
        }

        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;

            ii ii = (ii) o;

            if (first != ii.first) return false;
            if (second != ii.second) return false;

            return true;
        }

        public int hashCode() {
            int result = first;
            result = 31 * result + second;
            return result;
        }

        public int compareTo(ii o) {
            if (first != o.first) {
                return first < o.first ? -1 : 1;
            }
            if (second != o.second) {
                return second < o.second ? -1 : 1;
            }
            return 0;
        }


        public String toString() {
            return "{" +
                    "first=" + first +
                    ", second=" + second +
                    '}';
        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void print(Object... objects) {
            for (int i = 0; i < objects.length; i++) {
                if (i != 0) {
                    writer.print(' ');
                }
                writer.print(objects[i]);
            }
        }

        public void printLine(Object... objects) {
            print(objects);
            writer.println();
        }

        public void close() {
            writer.close();
        }

    }

    static class SegmentTreeFastIntervalAddSum {
        final int n;
        final long[] t;
        final long[] m;
        final boolean[] h;
        final long[] q;

        public SegmentTreeFastIntervalAddSum(int n) {
            this.n = n;
            t = new long[2 * n];
            m = new long[2 * n];
            h = new boolean[2 * n];
            q = new long[2 * n];
            for (int i = n; i < 2 * n; i++)
                q[i] = 1;
            for (int i = 2 * n - 1; i > 1; i -= 2)
                q[i >> 1] = q[i] + q[i ^ 1];
        }

        void modifierHelper(int i, long p) {
            t[i] += p * q[i];
            m[i] += p;
            h[i] = true;
        }

        void pop(int i) {
            if (h[i >> 1]) {
                t[i >> 1] = t[i] + t[i ^ 1] + m[i >> 1] * q[i >> 1];
            } else {
                t[i >> 1] = t[i] + t[i ^ 1];
            }
        }

        void popUp(int i) {
            for (; i > 1; i >>= 1)
                pop(i);
        }

        void push(int i) {
            if (h[i >> 1]) {
                modifierHelper(i, m[i >> 1]);
                modifierHelper(i ^ 1, m[i >> 1]);
                h[i >> 1] = false;
                m[i >> 1] = 0;
            }
        }

        void pushDown(int i) {
            int k;
            for (k = 0; (i >> k) > 0; k++)
                ;
            for (k -= 2; k >= 0; k--)
                push(i >> k);
        }

        public void modifyAdd(int a, int b, long v) {
            a += n;
            b += n;
            pushDown(a);
            pushDown(b);
            int ta = a;
            int tb = b;

            for (; a <= b; a = (a + 1) >> 1, b = (b - 1) >> 1) {
                if ((a & 1) != 0)
                    modifierHelper(a, v);
                if ((b & 1) == 0)
                    modifierHelper(b, v);
            }

            popUp(ta);
            popUp(tb);
        }

        public long querySum(int a, int b) {
            a += n;
            b += n;
            pushDown(a);
            pushDown(b);

            long res = 0;
            for (; a <= b; a = (a + 1) >> 1, b = (b - 1) >> 1) {
                if ((a & 1) != 0)
                    res += t[a];
                if ((b & 1) == 0)
                    res += t[b];
            }
            return res;
        }

        public void set(int i, long v) {
            modifyAdd(i, i, -querySum(i, i) + v);
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buffer = new byte[10000];
        private int cur;
        private int count;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public static boolean isSpace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public int read() {
            if (count == -1) {
                throw new InputMismatchException();
            }
            try {
                if (cur >= count) {
                    cur = 0;
                    count = stream.read(buffer);
                    if (count <= 0)
                        return -1;
                }
            } catch (IOException e) {
                throw new InputMismatchException();
            }
            return buffer[cur++];
        }

        public int readSkipSpace() {
            int c;
            do {
                c = read();
            } while (isSpace(c));
            return c;
        }

        public int nextInt() {
            int sgn = 1;
            int c = readSkipSpace();
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res = res * 10 + c - '0';
                c = read();
            } while (!isSpace(c));
            res *= sgn;
            return res;
        }

    }
}