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