program GreatestCommonDivisor;
var
X, Y, i, GCD: integer;
begin
writeln('Enter two integers X and Y:');
readln(X, Y);
if (X < 0) or (Y < 0) then
writeln('Error: Please enter positive integers.')
else
begin
i := 1;
GCD := 1;
while (i <= X) and (i <= Y) do
begin
if (X mod i = 0) and (Y mod i = 0) then
GCD := i;
i := i + 1;
end;
writeln('The greatest common divisor of ', X, ' and ', Y, ' is: ', GCD);
end;
end.