include <stdio.h>

int main() {

int i, n, m, s, j, c, f = 0;
scanf("%d %d", &n, &m);
for (int i = n; i <= m; i++) {
	s = 0;
	for (int j = 1; j * j <= i; j++) {
		if (i % j == 0 && j * j != i) {
			s = s + j + i / j;
		}
		if (j * j == i) {
			s = s + j;
		}
	}
	if (s - i == i) {
		f ++;
	}

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

}