import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
public class Main2869 {
public static void main(String[] args) throws IOException {
BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer st = new StringTokenizer(bf.readLine(), " ");
int A = Integer.parseInt(st.nextToken());
int B = Integer.parseInt(st.nextToken());
int V = Integer.parseInt(st.nextToken());
int cnt = (V - B) / (A - B);
if ((V - B) % (A - B) != 0)
cnt++;
System.out.println(cnt);
}
}