#include <fstream>
#include <iomanip>
#include <cstdlib>

using namespace std;

ifstream fin("minesweeper.in");
ofstream fout("minesweeper.out");

int N , M , D[16][16] , nr , timp , t , nm;

void f(int x,int y)
{
	nr = 0;
	while(nr!=nm)
	{
	timp++;
	 if(D[x][y]==1) D[x][y] = 2 ,  nr++;
	 else
		if(D[x][y]==2) D[x][y] = 0 , nr--;
		else
			D[x][y]++;
		x = rand() % N + 1 ,y = rand()%M + 1;
	}
	for(x=1;x<=N;++x)
			for(y=1;y<=M;++y)
				D[x][y] = 0;
}

int main()
{
	fin>>N>>M;
	nm = N*M;
	for(int i=1;i<=100;++i)
		f(rand()%N + 1 ,rand()%M+1);

	fout<<fixed<<setprecision(6)<<(double)timp/100;
	return 0;
}