三目YYDS!

#include<cstdio>
int main(){
    int y,m;
    scanf("%d %d",&y,&m);
    printf("%d",m==2?(y%4==0&&y%100!=0||y%400==0?29:28):(m<=7&&m%2==1||m>=8&&m%2==0?31:30));
}