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