#include <bits/stdc++.h>   using namespace std;   inline int read() {     int s = 0;     char c;     while ((c = getchar()) <  0  || c >  9 )       ;     do {       s = s * 10 + c -  0 ;     } while ((c = getchar()) >=  0  && c <=  9 );     return s;   }   const int N = 3010, M = 310;   int n, m, rp[M];   double f[M][2][N], tp[N][M];   priority_queue<pair<double, int> > h;   double nxdp(int i) {     int p = (++rp[i]) & 1;     if (rp[i] > n) return -1e9;     f[i][p][0] = 0;     for (int k = 1; k <= n; k++)       f[i][p][k] =           tp[k][i] * f[i][p ^ 1][k - 1] + (1 - tp[k][i]) * f[i][p][k - 1];     return f[i][p][n];   }   double work() {     int i, k;     double ans = 0;     for (i = 1; i <= m; i++)       for (k = 0; k <= n; k++) f[i][0][k] = 1;     for (i = 1; i <= m; i++) h.push(make_pair(nxdp(i), i));     for (i = 1; i <= n; i++) {       pair<double, int> t = h.top();       h.pop();       ans += t.first;       h.push(make_pair(nxdp(t.second), t.second));     }     return ans;   }   int main() {     int i, j;     n = read(), m = read();     for (i = 1; i <= n; i++)       for (j = 1; j <= m; j++) tp[i][j] = read() * 0.001;     printf( %.11lf n , work());     return 0;   }   