#include #define rep(i,n) for(int i=0;i<(int)(n);i++) using namespace std; using ll = long long ; using P = pair ; using pll = pair; constexpr int INF = 1e9; constexpr long long LINF = 1e17; constexpr int MOD = 1000000007; constexpr double PI = 3.14159265358979323846; int main(){ double a,b; cin >> a >> b; int ans = 50 * a + floor((50 * a + 0.3)/(0.8 + 0.2 * b)); cout << setprecision(20) << ans << endl; return 0; }