// Arup Guha
// 6/24/2025
// Solution to Kattis Problem: Getting Wood
// https://open.kattis.com/problems/gettingwood

using namespace std;
#include <bits/stdc++.h>

int main() {

    // Read in the line.
    string line;
    getline(cin, line);

    int idx = line.find("tree");

    if (idx >= 0)
        cout << idx << endl;
    else
        cout << "no trees here" << endl;

    return 0;
}