There is my program:

program t1070;

var t1,t2,o1,o2  :extended;
    Str          :string;
    i            :integer;

procedure makeIt(var x1,x2:extended;S:string);
var y1,y2,i :integer;
    sr      :string;
 begin
  i:=0;
  while s[i+1]=' ' do i:=i+1;
  sr:='';sr:=sr+s[i+1];sr:=sr+s[i+2]; val(sr,y1,i);
  sr:='';sr:=sr+s[i+4];sr:=sr+s[i+5]; val(sr,y2,i);
   x1:=y1+y2/60;
  i:=i+6;
  while s[i+1]=' ' do i:=i+1;
  sr:='';sr:=sr+s[i+1];sr:=sr+s[i+2]; val(sr,y1,i);
  sr:='';sr:=sr+s[i+4];sr:=sr+s[i+5]; val(sr,y2,i);
   x2:=y1+y2/60;
 end;

Function Time(t1,t2,r:extended):extended;
var r1,r2 :extended;
 begin
  r1:=t1;
  r2:=t2+r;
  if r1>r2 then r2:=r2+24;
  time:=r2-r1;
 end;

begin
Readln(Str);makeIt(t1,t2,str);
Readln(Str);makeIt(o1,o2,str);
for i:=-5 to 5 do begin
 if abs(time(t1,t2,i)-time(o1,o2,-i))<0.2666667 then
  break;
end;
writeln(abs(i));
end.