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