#include<iostream> using namespace std; int main(){ int n; cin>>n; switch(n){ case 1: cout<<"31"; break; case 2: cout<<"29"; break; case 3: cout<<"31"; break; case 4: cout<<"30"; break; case 5: cout<<"31"; break; case 6: cout<<"30"; break; case 7: cout<<"31"; break; case 8: cout<<"31"; break; case 9: cout<<"30"; break; case 10: cout<<"31"; break; case 11: cout<<"30"; break; case 12: cout<<"31"; break; } if((n>=13)||(n<=0)){ cout<<"Invalid."; } }