#include <iostream>
using namespace std;
int main(){
int year, month;
//cout<<"输入年份: ";
cin>>year;
bool leap = false;
if ((year%4==0 && year%100 !=0) || year%400 == 0)
leap = true;
// cout<<"输入月份: ";
cin>>month;
switch (month){
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
cout<<year<<month<<endl;
break;
case 4:
case 6:
case 9:
case 11:
cout<<year<<month<<endl;
break;
case 2:
if (leap)
cout<<"29"<<endl;
else
cout<<"28"<<endl;
break;
default:
break;
}
return 0;
}
c++

第三题 正确，没人？？