#include <iostream>
using namespace std;
main() {
int g,d,h,s=0,br=1;
cin >>g >>d >>h;
s=g;
while(s<h){
s=s-d;
s=s+g;
br++;
}
cout << br << endl;
return 0;
}
#include <iostream>
using namespace std;
main() {
int g,d,h,s=0,br=1;
cin >>g >>d >>h;
s=g;
while(s<h){
s=s-d;
s=s+g;
br++;
}
cout << br << endl;
return 0;
}