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