#include <bits/stdc++.h>
using namespace std;
int main() {
  double vp, vd, t, f, c;
  cin >> vp >> vd >> t >> f >> c;
  if (vp >= vd) {
    cout << 0 << endl;
    return 0;
  }
  int ans = 0;
  double begin = vp * t;
  while (1) {
    double T = begin * 1.0 / (vd - vp);
    begin += vp * T;
    if (begin - c >= 0)
      break;
    else {
      begin += (T + f) * vp;
      ans++;
    }
  }
  cout << ans << endl;
  return 0;
}
