import java.util.Scanner;

public class No604 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long A = sc.nextLong();
		long B = sc.nextLong();
		long C = sc.nextLong();
		long k,K,sum;
		for(k = 0;(A+B-1) * k < C;k++) {
		}
		K = A * k;
		for(sum = (A+B-1)*k;sum >= C;K--) {
			if(K % A == 0) {
				sum -= B;
			}else {
				sum -= 1;
			}
		}
		System.out.println(K + 1);
	}
}