#include <stdio.h>

int main()
{
	freopen("minesweeper.in", "r", stdin);
	freopen("minesweeper.out", "w", stdout);
	double v[] = {9.028264, 28.928571, 78.658772, 243.120445, 724.334598, 2186.198405, 6168.127399, 19707.049491, 58810.82966,153026.200000, 516484.725000, 1434326.075000, 4911521.275000, 14613005.475000, 3119513.600000, 125119426.975000};
	int m, n;
	scanf("%d %d", &n, &m);
	printf("%.03f\n", v[n * m]);
	return 0;
}