/* TLE expected */
#include <bits/stdc++.h>

int ri() {
	int n;
	scanf("%d", &n);
	return n;
}
int main() {
	int n = ri();
	std::map<int, int> a;
	for (int i = 0; i < n; i++) a[ri()]++;
	int64_t res = 0;
	for (auto &i : a) {
		for (auto &j : a) {
			res += (int64_t) i.second * j.second * (i.first % j.first); 
		}
	}
	std::cout << res << std::endl;
    return 0;
}