#include<iostream> using namespace std; int main(){ int n; cin>>n; if(n == 1 || n == 3 || n == 5 || n == 7 || n == 8 || n == 10 || n == 12){ cout<<"31"; }else if(n == 4 || n == 6 || n == 9 || n == 11){ cout<<"30"; }else if(n == 2){ cout<<"29"; }else{ cout<<"Invalid."; } return 0; }