#include <cstdio>

#include <cstring>

using namespace std;



const int N=1005;

int n, m;

double p[N][N][3], d[N][N];

const double eps=1e-10;

double abs(double x) { return x<0?-x:x; }

int main() {

	while(~scanf("%d%d", &n, &m)) {

		memset(d, 0, sizeof d);

		for(int i=1; i<=n; ++i)

			for(int j=1; j<=m; ++j)

				for(int k=0; k<3; ++k)

					scanf("%lf", &p[i][j][k]);

		for(int i=n; i>=1; --i)

			for(int j=m; j>=1; --j)

				if(!(i==n&&j==m) && abs(1-p[i][j][0])>eps)

					d[i][j]=(d[i][j+1]*p[i][j][1]+d[i+1][j]*p[i][j][2]+2)/(1-p[i][j][0]);

		printf("%.3f\n", d[1][1]);

	}

	return 0;

}