#include <bits/stdc++.h> #define int long long using namespace std; #define rep(i,s,n) for(int i = s;i<n;i++) #define repe(i,s,n) for(int i = s;i<=n;i++) #define pb push_back #define fi first #define se second typedef long long ll; typedef pair<int,int>pint; typedef vector<int>vint; typedef vector<pint>vpint; static const ll maxLL = (ll)1 << 62; const ll MOD=1000000007,INF=1e18; int dy[]={-1,0,1,0}; int dx[]={0,1,0,-1}; double a,b; signed main(){ cin>>a>>b; cout << setprecision(11)<< sqrt(b*b-a*a)<<endl; return 0; }