Квадраты и кубы final

// OK first tour region 17-18 B

# include <iostream>
# include <cmath>

using namespace std;

uint64_t pow2(uint64_t n) {
    uint64_t left = 1;
    uint64_t right = min(n, static_cast<uint64_t>(1'000'000'001));
    while (right - left > 1) {
        uint64_t mid = (left + right) / 2;
        if (mid * mid > n) {
            right = mid;
        } else {
            left = mid;
        }
    }
    return left;
}

uint64_t pow2_ceil(int64_t n) {
    if (n < 1) {
        return 1;
    }
    uint64_t left = 1;
    uint64_t right = min(n, static_cast<int64_t>(1'000'000'000));
    while (right - left > 1) {
        uint64_t mid = (left + right) / 2;
        if (mid * mid < n) {
            left = mid;
        } else {
            right = mid;
        }
    }
    return right;
}

int main() {
    int64_t a, b, k;
    cin >> a;
    cin >> b;
    cin >> k;
    int64_t res = 0;
    uint64_t pow_a = pow2_ceil(a);
    uint64_t pow_b = pow2(b);
    for (int64_t i = 1; i * i * i <= b; i++) {
        if (i * i * i < a) continue;
        int64_t left = max(pow2_ceil(i * i * i - k), pow_a);
        int64_t right = min(pow2(i * i * i + k), pow_b);
        res += max(right - left + 1, static_cast<int64_t>(0));
    }
    cout << res;
    return 0;
}