#include <algorithm>
#include <array>
#include <cmath>
#include <cstdio>
#include <deque>
#include <iomanip>
#include <iostream>
#include <numeric>
#include <optional>
#include <queue>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

int main() {
    string s;
    cin >> s;
    auto pos = s.find("pain");
    int32_t ans = -1;
    if (pos != string::npos) {
        int32_t cnt = 0;
        for (size_t i = 0; i < pos; ++i) {
            if (s[i] == 'p' && s[i + 1] == 'o' && s[i + 2] == 'n')
                ++cnt;
        }
        if (cnt >= 2)
            ans = cnt - 1;
    }
    cout << ans << endl;
    return 0;
}