#include<iostream> #include<cstdio> 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"<<endl;break; case 2:cout<<"29"<<endl;break; case 4: case 6: case 9: case 11:cout<<"30"<<endl;break; default:cout<<"invalid"<<endl;break; } return 0; }