#include <iostream>
using namespace std;
int main()
{
int month;
do
{
cout<<"Enter a number of month:"<<endl;
cin>>month;
if(month<=0||month>12)
{
cout<<"please check it again!"<<endl;
}
}while(month<=0||month>12)
switch(month)
{
case 2:
cout<<"28 or 29 days"<<endl;
break;
case 4:
case 6:
case 9:
case 11:
cout<<"30 days"<<endl;
break;
default:
cout<<"31 days"<<endl;
break;
}
}