#include <stdio.h>

int X, Y;
long long F[10000001];

int main(void) {
    scanf("%d %d", &X, &Y);
    for (int i = 1; i <= 10000000; i += 4) {
        for (int j = i; j <= 10000000; j += i) {
            F[j] += 4;
        }
    }
    for (int i = 3; i <= 10000000; i += 4) {
        for (int j = i; j <= 10000000; j += i) {
            F[j] -= 4;
        }
    }
    long long ans = 0;
    for (int i = X; i <= Y; i++) {
        if (ans < F[i]) ans = F[i];
    }
    printf("%lld\n", ans);
    return 0;
}