HIIT game

input/code.cpp: In function 'int main()':
input/code.cpp:20:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<s.length();i++) {
                            ^

#include <bits/stdc++.h>

using namespace std;

bool valid(vector<char>& s) {
    if(s.size() < 4) {
        return false;
    }
    int n = s.size();
    return s[n-1] == 'T' && s[n-2] == 'I' && s[n-3] == 'I' && s[n-4] == 'H';
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    string s;
    cin >> s;
    vector<char> stack;
    int cnt = 0;
    for(int i=0;i<s.length();i++) {
        stack.push_back(s[i]);
        if(valid(stack)) {
            cnt += 1;
            for(int j=0;j<4;j++) {
                stack.pop_back();
            }
        }
    }
    if(cnt%2 == 0) {
        cout << "Maija" << endl;
    } else {
        cout << "Uolevi" << endl;
    }
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED