#include <cstdio>
#include <numeric>
#include <vector>
typedef long long ll;

ll n, k;

int main() {
  #ifdef LOCAL
    freopen("!input.in", "r", stdin);
    freopen("!output.out", "w", stdout);
  #else
    freopen("Gold_coin.in", "r", stdin);
    freopen("Gold_coin.out", "w", stdout);
  #endif

  scanf("%lld %lld\n", &n, &k);

  std::vector<int> vector(n);
  std::iota(vector.begin(), vector.end(), 1);

  while (vector.size() != 1) {
    std::vector<int> erasepos;
    for (int i = 0; i < (int) vector.size(); i += k) {
      erasepos.push_back(i);
    }
    for (int i = 0; i < (int) erasepos.size(); ++i) {
      vector.erase(vector.begin() + erasepos[i] - i);
    }
  }

  printf("%d\n", vector[0]);
  return 0;
}