#include <bits/stdc++.h>
using namespace std;
double p, d, t, f, c;
int main(int argc, char const *argv[]) {
  scanf("%lf%lf%lf%lf%lf", &p, &d, &t, &f, &c);
  if (p >= d) {
    printf("0\n");
    return 0;
  }
  double pl = t * p, dl = 0;
  int ans = 0;
  while (pl < c) {
    double t1 = (pl - dl) / (d - p);
    dl = pl + t1 * p;
    ans++;
    double t2 = dl * 2 / d + f;
    pl = dl + t2 * p;
  }
  if (dl >= c) ans--;
  printf("%d\n", ans);
  return 0;
}
