#include <cstdio>

using namespace std;

long long calc(long long x){
    if(x == 0)
        return 0;

    long long res = 0;
    long long tmp;

    for(long long i = 1, tmp = x/i; x/i != 1; ++i, tmp = x/i){
        res += tmp;
    }

    res += x/2;

    if(x%2 == 1){
        res++;
    }

    return res;
}

int main(){
    long long n, m;

    scanf("%lld%lld", &n, &m);

    printf("%lld\n", calc(m)-calc(n-1));

    return 0;
}