C++ :

#include<bits/stdc++.h>
using namespace std;
int run(int x)
{
	return (x%100==0&&x%400==0)||(x%100!=0&&x%4==0);
}
int n,m;
int main()
{
	cin>>n>>m;
	int s=0; 
	if(run(n))s=1;
	switch(m)
	{
		case 1:cout<<31;break;
		case 2:cout<<28+s;break;
		case 3:cout<<31;break;
		case 4:cout<<30;break;
		case 5:cout<<31;break;
		case 6:cout<<30;break;
		case 7:cout<<31;break;
		case 8:cout<<31;break;
		case 9:cout<<30;break;
		case 10:cout<<31;break;
		case 11:cout<<30;break;
		case 12:cout<<31;break;
	}
   return 0;
}

Pascal :

program es5;
var a,b,c:integer;
begin
  readln(a,b);
  if b=1 then c:=31;
  if b=3 then c:=31;
  if b=5 then c:=31;
  if b=7 then c:=31;
  if b=8 then c:=31;
  if b=10 then c:=31;
  if b=12 then c:=31;
  if b=4 then c:=30;
  if b=6 then c:=30;
  if b=9 then c:=30;
  if b=11 then c:=30;
  if b=2 then if (a mod 4=0)and(a mod 100<>0) or (a mod 400=0) then c:=29
                     else c:=28;
  writeln(c);
end.