#include <algorithm>

int binaryGap(int n)
{
    int gap = 0;
    int run = -1; // -1 means no leading '1' has been seen yet

    while (n > 0) {
        if (n & 1) {
            if (run >= 0) {
                gap = std::max(gap, run);
            }
            run = 0;
        } else if (run >= 0) {
            ++run;
        }
        n >>= 1;
    }

    return gap;
}