private void computeAnswer() {
        long ans = getSumOfKthPowers(N);
        int coeff;//coeff of current subset contribution in inclusion exclusion sum
        for (int mask = 1; mask < (1 << primeCount); mask++) {
            long x = 1l;
            coeff = 1;
            for (int i = 0; i < primeCount; i++) {
                if (((1 << i) & mask) > 0) {
                    x = x * primes[i];
                    coeff *= -1;
                }
            }
            ans = ans + coeff * mul(pow(x, K), getSumOfKthPowers(N / x));
            if (ans < 0) ans += mod;
            if (ans >= mod) ans -= mod;
        }
        System.out.println(ans);
    }