#include<bits/stdc++.h>

using namespace std;
using ll=long long;
#define rep2(i, a, n) for(int i = (a); i < (n); i++)
#define rep(i, n) rep2(i,0,n)
#define inp(...) __VA_ARGS__; in(__VA_ARGS__)
#define ot(...) __VA_ARGS__; out(__VA_ARGS__)

void in() {} template <typename Head, typename... Tail> void in(Head&& head, Tail&&... tail) { cin>>head; in(forward<Tail>(tail)...); }
void out() {cout<<endl;} template <typename Head, typename... Tail> void out(Head&& head, Tail&&... tail) { cout<<head<<" "; out(forward<Tail>(tail)...); }

int main(){
  cin.tie(nullptr);ios_base::sync_with_stdio(false);
  //横の長さが x m、縦の長さが y m、厚みが h mm
  int x,y,h;
  inp(x,y,h);
  if(x<y)swap(x,y);

  x*=1000;
  y*=1000;

  int cnt=0;
  while(y>h){
    y/=2;
    h*=2;
    cnt++;
  }
  while(x>h){
    x/=2;
    h*=2;
    cnt++;
  }
  //out(x,y,h,cnt);

  cout<<cnt<<endl;
}