#include <iostream>
#include <cstdio>
#include <cmath>
using namespace std;
typedef long long ll;
#define int ll


signed main(void) {
  double a, b, ans;
  cin >> a >> b;

  if (a > b) {
    ans = a*a - b*b;
  } else if (a < b) {
    ans = b*b - a*a;
  } else if (a == b) {
    ans = a*a;
  }
  printf("%.10f\n", sqrt(ans));
  return 0;
}