Untitled

class Solution {
public:
    using ll = long long;
long long countSetBitsAtPosition(long long n, int i) {
    if (n < 0) return 0;

    // Use unsigned long long to avoid negative overflow issues
    unsigned long long uln = static_cast<unsigned long long>(n);
    unsigned long long cycleLength = 1ULL << (i + 1);
    unsigned long long completeCycles = uln / cycleLength;
    unsigned long long setBitsCount = completeCycles * (cycleLength / 2);

    unsigned long long remainingNumbers = uln % cycleLength;
    if (remainingNumbers >= cycleLength / 2) {
        setBitsCount += remainingNumbers - (cycleLength / 2) + 1;
    }

    return setBitsCount;
}

    ll helper(ll m, ll x){
        ll cnt = 0;
        for(int i = x; i < 64; i += x){
            cnt += countSetBitsAtPosition(m, i-1);
        }
        return cnt;
    }
    long long findMaximumNumber(long long k, int x) {
        ll l = 0, r = 1e15+1;
        while(l+1 != r){
            ll m = l + (r-l)/2;
            if(helper(m, x) > k)
                r = m;
            else
                l = m;
        }
        return l;
    }
};