package No400番台;

import java.util.Scanner;

public class Q418 {
	public static void main(String[] args) {
		new Q418().solver();
	}

	void solver() {
		Scanner sc = new Scanner(System.in);
		char[] c = sc.next().toCharArray();
		int ans = 0;
		for (int i = 0; i < c.length; i++) {
			if (c[i] - 'm' == 0)
				ans++;
		}
		System.out.println(ans);
	}
}