#include <fstream>
using namespace std;
ifstream f("minesweeper.in");
ofstream g("minesweeper.out");
const double V[]={0,2,9.006529,28.928571,86.46,255.037588,781.2875,2244.110481,6606.873469,19977.009498,59136.386097,178754.843368,535426.401724,388654546.719932,4808682.053956,13199340,43221366.569839,79199281.25,388654346.715331,158477749,3493224620.694068,158505257,31447222376.978};
int main()
{
    int n,m;
    f>>n>>m;
    g<<V[n*m];
    return 0;
}