target=10**6+1

d=[[] if i%2 else [2] for i in range(target)]
s,n=1,3
while n < target:
    if d[n]:
        m=n
        for k in d[n]:
            m=m*(k-1)/k
        s+=m
    else:
        for k in range(n,target,n):
            d[k].append(n)
        s=s+n-1
    n+=1

print s