#include <bits/stdc++.h>
using namespace std;
const int EXP = 1e2 + 5;
set<long long> mst, lev[EXP];
map<long long, long long> cnt;
long long solve(long long l, long long r, long long k, vector<long long> aux) {
  long long m = (l + r) / 2;
  if (r - l + 1 <= 2) return l + k - 1;
  if (k == 1 && r - l + 1 <= aux.back()) return m;
  cnt.clear();
  cnt[m - l] = 1;
  mst.clear();
  mst.insert(m - l);
  while (mst.empty() == false) {
    long long x = *mst.rbegin();
    mst.erase(x);
    if (x == 2) {
      cnt[1] += cnt[2] * 2;
      cnt[2] = 0;
      mst.insert(1);
      continue;
    }
    cnt[x / 2] += cnt[x];
    cnt[(x - 1) / 2] += cnt[x];
    if (x / 2 >= 1) mst.insert(x / 2);
    if ((x - 1) / 2 >= 1) mst.insert((x - 1) / 2);
  }
  long long sum = 0;
  for (long long x : aux) sum += cnt[x];
  if (k <= sum)
    return solve(l, m - 1, k, aux);
  else
    return solve(m + 1, r, k - sum, aux);
}
int main(void) {
  long long n, k;
  cin >> n >> k;
  if (k == 1)
    cout << 1 << endl;
  else if (k == 2)
    cout << n << endl;
  else {
    k -= 2;
    cnt[n - 2] = 1;
    lev[0].insert(n - 2);
    vector<long long> aux;
    for (int i = 0; lev[i].empty() == false; i++) {
      if (*lev[i].begin() == 2 && *lev[i].rbegin() == 3) {
        cnt[1] += cnt[2] * 2;
        cnt[2] = 0;
        lev[i].erase(2);
        lev[i + 1].insert(1);
      }
      if (*lev[i].rbegin() == 2) {
        cnt[1] += cnt[2] * 2;
        cnt[2] = 0;
        lev[i].erase(2);
        lev[i].insert(1);
      }
      for (long long x : lev[i]) {
        cnt[x / 2] += cnt[x];
        cnt[(x - 1) / 2] += cnt[x];
        if (x / 2 >= 1) lev[i + 1].insert(x / 2);
        if ((x - 1) / 2 >= 1) lev[i + 1].insert((x - 1) / 2);
      }
      if (lev[i].size() == 1) {
        long long x = *lev[i].begin();
        if (k > cnt[x])
          k -= cnt[x];
        else {
          aux = vector<long long>{x};
          break;
        }
      } else {
        long long x = *lev[i].begin();
        long long y = *lev[i].rbegin();
        if (k > cnt[x] + cnt[y])
          k -= cnt[x] + cnt[y];
        else {
          if (x % 2 == 1)
            aux = vector<long long>{x, y};
          else {
            if (k <= cnt[y])
              aux = vector<long long>{y};
            else {
              k -= cnt[y];
              aux = vector<long long>{x};
            }
          }
          break;
        }
      }
    }
    cout << solve(2, n - 1, k, aux) << endl;
  }
  return 0;
}
