Dekisugi in Trouble

$Dekisugi$ is an intelligent kid who can solve any kind of maths problem. He is consistently the top performer of his class. But this time instead of solving an easy problem he decides to spend time with $Shizuka$ . He has asked you to solve this easy problem(at least easy for $Dekisugi$) so that he could go out with her. You are given two integers $n$ and $m$ and you are supposed to find small