{$APPTYPE CONSOLE}

var
 t1,t2,t3,t4: real;
 a1,a2,a3,a4: integer;

 k1,k2: integer;
 diff1, diff2: integer;

 i: integer;
begin
 Assign(input,'input.txt'); reset(input);
 Assign(output,'output.txt'); rewrite(output);

 readln(t1,t2);
 read(t3,t4);

 if t1 > t2 then t2 := t2 + 24;
 if t3 > t4 then t3 := t3 + 24;

 a1:=round(t1)*60;
 a2:=round(t2)*60;
 a3:=round(t3)*60;
 a4:=round(t4)*60;

 if  (t1-trunc(t1))>0.09 then  a1:=a1 + round((t1-trunc(t1))*100)
    else   a1:=a1  + round((t1-trunc(t1))*10);
  if  (t2-trunc(t2))>0.09 then  a2:=a2  + round((t1-trunc(t1))*100)
    else   a2:=a2  + round((t2-trunc(t2))*10);
  if  (t3-trunc(t3))>0.09 then  a3:=a3  + round((t3-trunc(t3))*100)
    else   a3:=a3  + round((t3-trunc(t3))*10);
  if  (t4-trunc(t4))>0.09 then  a4:=a4  + round((t4-trunc(t4))*100)
    else   a4:=a4  + round((t4-trunc(t4))*10);

 for i:=0 to 5  do
  begin
   diff1 := a1-i*60;
   diff2 := a4-i*60;
    k1:= abs(abs(diff1-a2));
    //writeln(k1 div 60,':',k1 mod 60, '   ',diff1,'-',a2,'  ', abs(diff1-a2));
    k2:= abs(abs(diff2-a3));
    //writeln(k1 div 60,':',k1 mod 60, '   ',diff2,'-',a3,'  ', abs(diff2-a3));

    //writeln(diff1 div 60,':', diff1 mod 60, '   ', t2:2:2);
    //writeln(t3:2:2,'   ',diff2 div 60,':', diff2 mod 60);


    if  abs(k1-k2)<=10 then writeln(i);
   end;
end.