#include #define FOR(i,a,b) for(int i = (a); i < (b); ++i) #define REP(i,n) FOR(i,0,n) #define SZ(n) (int)(n).size() #define ALL(n) (n).begin(), (n).end() #define MOD % 1000000007 using namespace std; typedef long long LL; typedef vector VI; int main() { int a, b; cin >> a >> b; cout << 50 * a + floor(50 * a / (0.8 + 0.2 * b)) << endl; return 0; }