#include <bits/stdc++.h>
using namespace std;
const int N = 1e3 + 5;
int n;
double p[N][N], E[N], g[N], f[N];
bool vis[N];
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= n; j++) scanf("%lf", &p[i][j]), p[i][j] /= 100.0;
  for (int i = 1; i <= n; i++) g[i] = 1 - p[i][n];
  vis[n] = 1;
  for (int i = 1; i <= n; i++) {
    double mn = 1e18;
    int id = 0;
    for (int j = 1; j <= n; j++)
      if (!vis[j] && (f[j] + 1) / (1 - g[j]) < mn) {
        mn = (f[j] + 1) / (1 - g[j]);
        id = j;
      }
    vis[id] = 1;
    E[id] = (f[id] + 1) / (1 - g[id]);
    for (int j = 1; j <= n; j++)
      if (!vis[j])
        f[j] += g[j] * p[j][id] * E[id], g[j] = g[j] * (1 - p[j][id]);
  }
  printf("%.6lf\n", E[1]);
  return 0;
}
