#include <bits/stdc++.h>
using namespace std;
const int N = 1005;
template <typename T>
void read(T &x) {
  x = 0;
  int f = 1;
  char c = getchar();
  for (; !isdigit(c); c = getchar())
    if (c == '-') f = -1;
  for (; isdigit(c); c = getchar()) x = (x << 1) + (x << 3) + c - '0';
  x *= f;
}
int n;
double g[N][N];
double E[N], prod[N];
bool vis[N];
int main() {
  read(n);
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= n; j++) {
      int x;
      read(x);
      g[i][j] = 1. * x / 100;
    }
  if (n == 1) return puts("0");
  vis[n] = true;
  for (int i = 1; i < n; i++) {
    E[i] = 1;
    prod[i] = 1 - g[i][n];
  }
  for (int i = 1; i <= n; i++) {
    double low = 1e18;
    int pos = 0;
    for (int j = 1; j <= n; j++)
      if (!vis[j] && E[j] / (1 - prod[j]) < low)
        low = E[j] / (1 - prod[j]), pos = j;
    if (pos == 1) return printf("%.10lf\n", E[1] / (1 - prod[1])), 0;
    vis[pos] = true;
    for (int j = 1; j <= n; j++)
      E[j] += E[pos] / (1 - prod[pos]) * g[j][pos] * prod[j],
          prod[j] *= (1 - g[j][pos]);
  }
  return 0;
}
