#include<iostream>
#include<vector>
#include<string>
using namespace std;
int main(){
    int N;
    cin>>N;
    vector<string>validDoors;
    for(int i=0;i<N;i++){
       string doorCode;
       int securityLevel;
       cin>>doorCode>>securityLevel;
       if(securityLevel>=50){
           validDoors.push_back(doorCode+":"+to_string(securityLevel));
       }
    }
    if(validDoors.empty()){
        cout<<"No valid doors"<<endl;
    }
    else{
        for(const string&door: validDoors){
            cout<<door<<endl
        }
    }    
    return 0;
}