import java.util.HashMap;

public class Euler351 {
    static HashMap<Long, Long> memo = new HashMap<>();

    static long sumTotient(long n) {
        Long cached = memo.get(n);
        if (cached != null)
            return cached;
        long total = n * (n + 1) / 2;
        long left = 2;
        while (left <= n) {
            long quotient = n / left;
            long right = n / quotient;
            total -= (right - left + 1) * sumTotient(quotient);
            left = right + 1;
        }
        memo.put(n, total);
        return total;
    }

    public static String solve() {
        memo.put(0L, 0L);
        memo.put(1L, 1L);
        long order = 100000000L;
        long triangle = order * (order + 1) / 2;
        long visible = sumTotient(order);
        long hidden = triangle - visible;
        long ans = hidden * 6;
        return String.valueOf(ans);
    }

    public static void main(String[] args) {
        System.out.println(solve());
    }
}