#include<bits/stdc++.h>
using namespace std;
int main(){
    int y,m;
    cin>>y>>m;
    if(m==1||m==3||m==5||m==7||m==8||m==10||m==12)
        cout<<"31";
        return 0;
    if(m==4||m==6||m==9||m==11)
        cout<<"30";
       return 0;
    if(m==2){
        if(y%400==0||y%4==0&&y%100!=0)
        cout<<"29";
       return 0;
    }
    else cout<<"28";
    return 0;
}
`````
20pts......