#include <bits/stdc++.h>
using namespace std;
double vp, vd, t, f, c;
int cal() {
  double p = t * vp;
  double v = vd - vp;
  int x = 0;
  p += p / v * vp;
  while (p < c) {
    x++;
    p += (p / vd + f) * vp;
    p += p / v * vp;
  }
  return x;
}
int main() {
  scanf("%lf%lf%lf%lf%lf", &vp, &vd, &t, &f, &c);
  if (vp >= vd)
    printf("0\n");
  else
    printf("%d\n", cal());
  return 0;
}
