在拐~

#include <stdio.h>

#include <cstring>

#include <iostream>

#include <map>

#include <cmath>

template <class T>

inline bool rd(T &ret) {

    char c; int sgn;

    if(c=getchar(),c==EOF) return 0;

    while(c!='-'&&(c<'0'||c>'9')) c=getchar();

    sgn=(c=='-')?

-1:1;

    ret=(c=='-')?0:(c-'0');

    while(c=getchar(),c>='0'&&c<='9') ret=ret*10+(c-'0');

    ret*=sgn;

    return 1;

}

template <class T>

inline void pt(T x) {

    if (x <0) {

        putchar('-');

        x = -x;

    }

    if(x>9) pt(x/10);

    putchar(x%10+'0');

}

using namespace std;

typedef unsigned long long ull;

const double eps = 1e-10;

const int N = 1005;

int n, m;

double mp[N][N][3], dp[N][N];

double solve(){

	dp[n][m] = 0;

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

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

		{

			if(i == n && j == m)continue;

			if(fabs(mp[i][j][0] - 1.0) < eps)

			{

				dp[i][j] = 0;

			}

			else

			{

				dp[i][j] = mp[i][j][1] * dp[i][j+1] + mp[i][j][2] * dp[i+1][j];

				dp[i][j] += 2.0;

				dp[i][j] /= (1 - mp[i][j][0]);

			}

		}

	return dp[1][1];

}

void input(){

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

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

			scanf("%lf %lf %lf", &mp[i][j][0], &mp[i][j][1], &mp[i][j][2]);

}

int main(){

    while(cin>>n>>m){

        input();

        printf("%.3f\n", solve());

    }

    return 0;

}