-- JSRUN引擎2.0,支持多达30种语言在线运行,全仿真在线交互输入输出。
local number = {0,0}
tonumber(io.read())
sum_a = 0
sum_b = 0
for i = 1, (number[1] / 2) do
if number[1] % i == 0 then
sum_a = i + sum_a
end
end
for i = 1, (number[2] / 2) do
if number[2] % i == 0 then
sum_b = i + sum_b
end
end
if sum_a==number[2] and sum_b==number[1] then
print("yes")
else
print("no")
end