#include <bits/stdc++.h> using namespace std; char a[10010];

int main() { cin >> a; int l = strlen(a); bool x = 0; int cnt = 0; for (int i = 0; i < l; i++) { if (a[i] == '3') { x = 1; } cnt = cnt + (a[i] - '0'); } if (cnt % 3 == 0 || x == 1) { cout << "guo"; } else { cout << a; } }