# 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"<<endl; break; case 4: case 6: case 9: case 11: cout<<"30"<<endl; break; case 2: cout<<"29"<<endl; break; default: cout<<"Invalid."<<endl; } }