function dividers(x: integer): integer;
var s, i: integer;
begin
s := 0;
for i := 1 to x - 1 do
if x mod i = 0 then
s := s + i;
dividers := s
end;

var
a, b: integer;

begin
Write('Введите два натуральных числа: '); Read(a, b);
if (dividers(a) = b) and (dividers(b) = a) then
WriteLn('YES')
else
WriteLn('NO');
ReadLn
end.