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