include <stdio.h>

int main() {

int a, s, d = 0, f = 0, g, n, m;
scanf("%d %d", &n, &m);

for (int a = n; a <= m; a++) {

	s = a;

	if (a > 10000) {
		break;
	}

	for (int j = 1; j < s; j++) {

		if (s % j == 0) {
			d += j;
		}
	}

	if (d == s) {
		f++;
	}

	d = 0;
}

printf("%d", f);
return 0;

}