from math import sqrt
L = 130000; ds = [1]*L
for i in range(2, int(sqrt(L))):
    for j in range(i+1, L//i):
        ds[i*j]+= i+j
an = []
for i in range(2, L):
    if ds[i] < i and ds[ds[i]] == i: an+= [ds[i], i]

N = int(input("Limit? "))
print ("Amicable sum less than",N,"=", sum(a for a in an if a<N))