#include using namespace std; #define ALL(obj) (obj).begin(), (obj).end() #define FOR(i, a, b) for(int i = (a); i < (b); ++i) #define REP(i, n) for(int i = 0; i < (n); ++i) #define endl "\n" #define pb push_back #define elif else if #define coutdb fixed #define MOD 1000000007 const int dx[]={1,0,-1,0}, dy[]={0,-1,0,1}; const int dx_8[]={1,1,0,-1,-1,-1,0,1}, dy_8[]={0,-1,-1,-1,0,1,1,1}; typedef long long ll; typedef unsigned long long ull; template inline T GCD(T a,T b){T c;while(b!=0){c=a%b;a=b;b=c;}return a;} template inline T LCM(T a,T b){T c=GCD(a,b);a/=c;return a*b;} template inline T nCr(T a,T b){T i,r=1;for(i=1;i<=b;i++){r*=(a+1-i);r/=i;}return r;} template inline T nHr(T a,T b){return nCr(a+b-1,b);} template inline T POW(T a,T b){int i,r=1;for(i=1;i<=b;i++){r*=a;}return r;} int main(){ cin.tie(0); ios::sync_with_stdio(false); double r, d; cin >> r >> d; double a = pow(d, 2) - pow(r, 2); cout << coutdb << sqrt(a) << endl; return 0; }