//No.418 ミンミンゼミ
#include<iostream>
#include<string>
using namespace std;
int main()
{
	string S;
	cin >> S;
	string cicade = "min";
	int now_min = 0;
	int min_cnt = 0;
	for (int i = 0; i < S.length(); i++) {
		if (S[i] == cicade[now_min]) {
			now_min++;
		}
		if (now_min == 2) {
			min_cnt++;
			now_min = 0;
		}
	}
	cout << min_cnt << endl;
	return 0;
}