#include<iostream> #include<iomanip> 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; }