#include <bits/stdc++.h>
using namespace std;
int n;
double p[1020][1020];
double m[1020], A[1020], B[1020];
bool vis[1020];
int dcmp(double x) {
  if (fabs(x) < 1e-12) return 0;
  return x < 0 ? -1 : 1;
}
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;
    }
  }
  for (int i = 1; i <= n; ++i) A[i] = B[i] = 1, m[i] = 1e30;
  m[n] = 0;
  for (int i = 1; i <= n; ++i) {
    int u = -1;
    double tmp = 1e10;
    for (int j = 1; j <= n; ++j) {
      if (m[j] < tmp && !vis[j]) tmp = m[j], u = j;
    }
    vis[u] = 1;
    for (int x = 1; x <= n; ++x) {
      if (vis[x]) continue;
      B[x] += A[x] * p[x][u] * m[u];
      A[x] *= 1 - p[x][u];
    }
    for (int x = 1; x <= n; ++x) {
      if (vis[x]) continue;
      if (dcmp(1 - A[x]) == 0)
        m[x] = 1e30;
      else
        m[x] = B[x] / (1 - A[x]);
    }
  }
  printf("%.12lf\n", m[1]);
  return 0;
}
