#include <math.h>
#include <stdio.h>

int main() {
	int n, m, count = 0;
	scanf("%d%d", &n, &m);
	for (int i = n; i <= m; i++) {
		int flag = 0;
		for (int j = 1; j <= sqrt(i); j++) {
			if (j * j == i) {
				flag = flag + j;
			} else if (i % j == 0) {
				flag = flag + j + i / j;
			}
		}
		if (flag - i == i) {
			count++;
		}
	}
	printf("%d", count);
	return 0;
}