import java.util.Scanner;


public class Main_yukicoder176 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int a = sc.nextInt();
        int b = sc.nextInt();
        int t = sc.nextInt();

        int m  = (t + b - 1) / b;

        long l = ((long)t / lcm(a, b) - 1) * lcm(a, b) / b;

        int min = Integer.MAX_VALUE;
        for (int i = m; i >= 0 && i >= l; i--) {
        	if (i * b >= t) {
        		min = Math.min(min, i * b);
        	} else {
        		min = Math.min(min, (t - i * b + a - 1) / a * a + i * b);
        	}
        }

        System.out.println(min);

        sc.close();
    }

    private static long lcm(int n, int m) {
		return (long)n / gcd(n, m) * m;
	}

	private static int gcd(int n, int m) {
		if (m == 0) {
			return n;
		} else {
			return gcd(m, n % m);
		}
	}
}