题解

#include <iostream>
using namespace std;
int main(){
int a, b;
cin >> a >> b;
if (a%40 && a%100!=0 || a%4000){
switch (b){
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12: printf("31\n") ; break;
case 4:
case 6:
case 9:
case 11: printf("30\n") ; break;
default: printf("29\n") ;
}
}else{
switch (b){
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12: printf("31\n") ; break;
case 4:
case 6:
case 9:
case 11: printf("30\n") ; break;
default: printf("28\n") ;
}
}
return 0;
}