import java.io.*;
import java.util.*;
import java.math.*;
import java.lang.*;
import static java.lang.Math.*;

public class Sol
{

    static long mod=1000000007;

    public static void main(String args[]) throws Exception
    {
        InputReader in;
        PrintWriter w;
        boolean online = false;
        String fileName = "input";

        if (online)
        {
            in = new InputReader(new FileInputStream(new File(fileName + ".in")));
            w = new PrintWriter(new FileWriter("out.txt"));
        }
        else
        {
            in = new InputReader(System.in);
            w = new PrintWriter(System.out);
        }

        //int T = in.nextInt();
        int T=1;

        for (int t = 1; t <= T; t++)
        {
            char c[]=in.next().toCharArray();
            int t1=0, t2=0, c1=0, c2=0, flag=0, max=0;

            if(c[0]==':') flag=1;

            for(int i=0;i<c.length-1;i++)
            {
                if(c[i]==':' && c[i+1]==')') t1++;
                else if(c[i]=='(' && c[i+1]==':') t2++;
            }

            max=max(t1,t2);

            for(int i=0;i<c.length-1;i++)
            {
                if(c[i]==':' && c[i+1]==')') c1++;

                else if(c[i]=='(' && c[i+1]==':')
                {
                    c2++;
                    if(i+2<=c.length-1 && c[i+2]==')') {
                        c1++;
                        if(flag==1) c2++;
                    }
                    max=max(max, (c2 + (t1 - c1)));
                    if(flag==1 && i+2<=c.length-1 && c[i+2]==')') c2--;
                    i++;
                }
            }

            w.println(max);
        }

        w.close();
    }

    static int arr[];
    static int size[];

    static void initialize(int n)
    {
        for(int i=0;i<=n;i++)
        {
            arr[i]=i;
            size[i]=1;
        }
    }

    static int root(int r)
    {
        while(arr[r]!=r)
        {
            arr[r]=arr[arr[r]];
            r=arr[r];
        }

        return r;
    }

    static void union(int u,int v)
    {
        int r1=root(u);
        int r2=root(v);

        if(r1!=r2)
        {
            if(size[r1]<size[r2])
            {
                arr[r1]=arr[r2];
                size[r2]+=size[r1];
            }

            else
            {
                arr[r2]=arr[r1];
                size[r1]+=size[r2];
            }
        }
    }

    private static long gcd(long a, long b)
    {
        while (b > 0)
        {
            long temp = b;
            b = a % b; // % is remainder
            a = temp;
        }
        return a;
    }

    private static long gcd(long[] input)
    {
        long result = input[0];

        for(int i = 1; i < input.length; i++)
            result = gcd(result, input[i]);

        return result;
    }

    private static long lcm(long a, long b)
    {
        return a * (b / gcd(a, b));
    }

    private static long lcm(long[] input)
    {
        long result = input[0];

        for(int i = 1; i < input.length; i++)
            result = lcm(result, input[i]);

        return result;
    }

    public static void Array_2dsort(Integer[][] a)
    {
        Arrays.sort(a, new Comparator<Integer[]>()
        {
            public int compare(Integer[] int1, Integer[] int2)
            {
                Integer numOfKeys1 = int1[1];       //about which column u want to sort
                Integer numOfKeys2 = int2[1];
                return numOfKeys1.compareTo(numOfKeys2);
            }
        });
    }

    static long powmod(long x,long n,long m)        //(a/b)%mod = (a * (b^(m-2))%mod  here --> x=a, n=mod-2, m=mod
    {
    if (n == 0)
            return 1;
        else if (n%2==0)
            return powmod(((x%m)*(x%m))%m,n/2,m);
    else if(n%2==1)
            return (((x%m)*powmod(((x%m)*(x%m))%m,(n-1)/2,m))%m);
    else
            return 0;
    }


    static class InputReader
    {

                private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;

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

        public int read()
        {
            if (numChars==-1)
                throw new InputMismatchException();

            if (curChar >= numChars)
            {
                curChar = 0;
                try
                {
                    numChars = stream.read(buf);
                }
                catch (IOException e)
                {
                    throw new InputMismatchException();
                }

                if(numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public String nextLine()
        {
            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
        public int nextInt()
        {
            int c = read();

            while(isSpaceChar(c))
                c = read();

            int sgn = 1;

            if (c == '-')
            {
                sgn = -1;
                c = read();
            }

            int res = 0;
            do
            {
                if(c<'0'||c>'9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c));

            return res * sgn;
        }

        public long nextLong()
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            long res = 0;

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

        public double nextDouble()
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.')
            {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, nextInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.')
            {
                c = read();
                double m = 1;
                while (!isSpaceChar(c))
                {
                    if (c == 'e' || c == 'E')
                        return res * Math.pow(10, nextInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }

        public String readString()
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do
            {
                res.appendCodePoint(c);
                c = read();
            }
            while (!isSpaceChar(c));

            return res.toString();
        }

        public boolean isSpaceChar(int c)
        {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public String next()
        {
            return readString();
        }

        public interface SpaceCharFilter
        {
            public boolean isSpaceChar(int ch);
        }
    }

}