#include #include using namespace std; int N; int bitCount(int n) { int count = 0; while (n > 0) { if (n & 1) count++; n = n >> 1; } return count; } int result = 0; bool found = false; vector visit; void solve(int p) { if (found) return; visit[p] = true; ++result; int bitNum = bitCount(p); if (p + bitNum == N) { ++result; found = true; return; } if (p + bitNum < N) { if (!visit[p + bitNum]) { solve(p + bitNum); if (!found) --result; } } if (found) return; if (p - bitNum > 0) { if (!visit[p - bitNum]) { solve(p - bitNum); if (!found) --result; } } } int main() { cin >> N; visit.resize(N + 1); solve(1); if (!found) { cout << -1 << endl; } else { cout << result << endl; } }