#include <bits/stdc++.h>
using namespace std;
int n;
double tab[1007][1007];
int jusz[1007];
double tak[1007];
double wyn[1007];
double tam;
double tu;
double nie;
int v;
int zero(double v) { return abs(v) < 0.000000001; }
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= n; j++) {
      scanf("%lf", &tab[i][j]);
      tab[i][j] /= 100.0;
    }
  }
  jusz[n] = 1;
  for (int i = 1; i < n; i++) {
    tak[i] = tab[i][n];
    wyn[i] = tak[i];
  }
  for (int h = 1; h < n; h++) {
    tam = 1000000000.0;
    v = -1;
    for (int i = 1; i <= n; i++) {
      if (jusz[i] || zero(tak[i])) continue;
      nie = 1.0 - tak[i];
      if (zero(nie)) {
        tu = wyn[i];
      } else {
        tu = wyn[i] / tak[i] + (nie / (1.0 - nie));
      }
      if (tu < tam) {
        tam = tu;
        v = i;
      }
    }
    if (v == -1) break;
    jusz[v] = 1;
    wyn[v] = tam;
    for (int i = 1; i <= n; i++) {
      if (jusz[i] || zero(tab[i][v])) continue;
      nie = 1.0 - tak[i];
      wyn[i] += nie * tab[i][v] * (wyn[v] + 1.0);
      nie *= (1.0 - tab[i][v]);
      tak[i] = 1.0 - nie;
    }
  }
  printf("%.9lf\n", wyn[1]);
  return 0;
}
