package knightguard;

    import java.util.ArrayList;
    import java.util.HashSet;
    import java.util.Scanner;
    import java.util.Set;

    public class KnightGuard {

        static class Position {

            int x;
            int y;

            public Position(int x, int y) {
                this.x = x;
                this.y = y;
            }

            public boolean equals(Position p) {
                if (p.x == x && p.y == y) {
                    return true;
                }
                return false;
            }

            @Override
            public String toString() {
                return x + "," + y;
            }

        }

        ArrayList<Position> knightPositions;
        int size;
        int no_of_knights;

        public KnightGuard(int size, int k, ArrayList<Position> knightPositions) {
            this.knightPositions = knightPositions;
            no_of_knights = k;
            this.size = size;
        }

        public int getSafePositions() {
            Set<Position> safePos = new HashSet<>();
            for (Position p : knightPositions) {
                if (isValid(p.x - 2, p.y - 1)) {
                    safePos.add(new Position(p.x - 2, p.y - 1));
                }
                if (isValid(p.x - 2, p.y + 1)) {
                    safePos.add(new Position(p.x - 2, p.y + 1));
                }
                if (isValid(p.x + 2, p.y - 1)) {
                    safePos.add(new Position(p.x + 2, p.y - 1));
                }
                if (isValid(p.x + 2, p.y + 1)) {
                    safePos.add(new Position(p.x + 2, p.y + 1));
                }

                if (isValid(p.x - 1, p.y - 2)) {
                    safePos.add(new Position(p.x - 1, p.y - 2));
                }
                if (isValid(p.x - 1, p.y + 2)) {
                    safePos.add(new Position(p.x - 1, p.y + 2));
                }
                if (isValid(p.x + 1, p.y - 2)) {
                    safePos.add(new Position(p.x + 1, p.y - 2));
                }
                if (isValid(p.x + 1, p.y + 2)) {
                    safePos.add(new Position(p.x + 1, p.y + 2));
                }
            }

            return safePos.size();
        }

        private boolean isValid(int x, int y) {
            if (x < 0 || x >= size || y < 0 || y >= size) {
                return false;
            }

            if (knightPositions.contains(new Position(x, y))) {
                return false;
            }

            return true;
        }

        public static void main(String[] args) {
            Scanner s = new Scanner(System.in);
            int size = s.nextInt();
            int knights = s.nextInt();
            ArrayList<Position> knightPos = new ArrayList<>();
            for (int i = 0; i < knights; i++) {
                int x = s.next().charAt(0) - 'a';
                int y = s.nextInt() - 1;
                knightPos.add(new Position(x, y));
            }

            KnightGuard knightGuard = new KnightGuard(size, knights, knightPos);
            System.out.println(knightGuard.getSafePositions());

        }

    }