https://www.acmicpc.net/problem/2869
import java.util.Scanner;
public class Main {
public static void main(String args[]) {
Scanner s= new Scanner(System.in);
int a=s.nextInt();
int b=s.nextInt();
int v=s.nextInt();
int k=(v-b)/(a-b);
int m=(v-b)%(a-b);
if(m==0) System.out.format("%d",k);
else System.out.format("%d",k+1);
}
}