import std.stdio;
import std.conv, std.array, std.algorithm, std.string;
import std.math, std.random, std.range, std.datetime;
import std.bigint;

void main(){
	int a, b;
	{
		int[] tmp = readln.chomp.split.map!(to!int).array();
		a = tmp[0], b = tmp[1];
		}
	
	real ans;
	if(a < b){
		ans = sqrt(cast(real)(b * b - a * a));
		}
	else if(a == b){
		ans = sqrt(cast(real)(a * a + b * b));
		}
	else{
		ans = sqrt(cast(real)(a * a - b * b));
		}
	
	writefln("%4.8f", ans);
	}