#include <bits/stdc++.h>
using namespace std;
 
int main() {
str N;
cin >> N;
  
if(str.at(0)=="7"){
  cout << "yes" <<endl;
}
  
else if(str.at(1)=="7"){
  cout << "yes" <<endl;
}
  
else if(str.at(2)=="7"){
  cout << "yes" <<endl;
}
  
else{
  cout << "No" << endl;
}
  
}