#include <bits/stdc++.h> using namespace std; typedef long long ll; #define rep(i,n) for(int i=0;i<n;i++) static const double pai=3.14159265358979; int main(){ double s,a,b; cin>>a>>b; s = -8.245 + 6.807 * a + 7.073 * b*2*pai; cout<<setprecision(18)<<s<<endl; return 0; }