#include<iostream> uslng namespace std; int main(){ int n; cin>>n; switch(n){ case 1: case 3: case 5: case 7: case 8: case 10: case 12: cout<<31; break; case 4: case 6: case 9: case 11: cout<<30; break; case 2: cout<<29; break; default: cout<<"lnvalid."; } return 0; }