#include<iostream>
using namespace std;

int main() {
    int N;
    cin >> N;
    
    bool found = false;
    
    for(int i = 0; i < N; i++) {
        string code;
        int level;
        cin >> code << level;
        if(level >= 50) {
            cout << code << ":" << level << endl;
            found = true;
        }
    }
    if(!found) {
        cout << "No valid doors";
    }
    return 0;
}