import math
import sys

def main():
    input = sys.stdin.read().split()
    N = int(input[0])
    M = int(input[1])

    max_n = max(N, M)
    sigma = [0] * (max_n + 2)  # Precompute sigma for 1..max_n

    # Precompute the sum of divisors (σ) using a sieve approach
    for i in range(1, max_n + 1):
        for j in range(i, max_n + 1, i):
            sigma[j] += i

    sum_prev = 0
    max_sum = 0

    for x_current in range(1, N + 1):
        if x_current <= M:
            delta = sigma[x_current]
        else:
            delta = 0
            sqrt_x = int(math.isqrt(x_current))
            for i in range(1, sqrt_x + 1):
                if x_current % i == 0:
                    j = x_current // i
                    if i <= M:
                        delta += i
                    if j != i and j <= M:
                        delta += j

        sum_prev += delta
        current_sum = x_current * M - sum_prev
        if current_sum > max_sum:
            max_sum = current_sum

    print(max_sum)

if __name__ == "__main__":
    main()