C++ :

#include<bits/stdc++.h>
using namespace std;
int a,b,c,t,s;
char d;
int main()
{
	cin>>a>>d>>b>>d>>c;
	if(a%100==0)
	{
		if(a%400==0)
		t=29;
		else
		t=28;
	}
	else 
	{
		if(a%4==0)
		t=29;
		else
		t=28;
	}
	int f[12]{31,t,31,30,31,30,31,31,30,31,30,31};
	for(int i=0;i<b-1;i++)
	s+=f[i];
	cout<<s+c;
   return 0;
}

Pascal :

program t14044;
const day:array [1..12] of longint=(31,28,31,30,31,30,31,31,30,31,30,31);
var
  st,ch1,ch2,ch3:string;
  y,m,d,len,p,max,i:longint;
  c:integer;
begin
  readln(st);
  len:=length(st);

  p:=pos('-',st);
  ch1:=copy(st,1,p-1);
  val(ch1,y,c);

  delete(st,1,p);
  p:=pos('-',st);
  ch2:=copy(st,1,p-1);
  val(ch2,m,c);

  ch3:=copy(st,p+1,len);
  val(ch3,d,c);

  for i:=1 to m-1 do
    begin
      if i<>2 then max:=max+day[i] else
      if (y mod 4=0) and (y mod 100<>0) or (y mod 400=0) then max:=max+29
      else max:=max+28;
    end;
  max:=max+d;
  writeln(max);
end.