#include <bits/stdc++.h>
using namespace std;
const int N = 110000;
int s1, s2;
int n, a[N];
int mi[17][N * 2], ma[17][N * 2];
int BB[N * 2];
int getmi(int l, int r) {
  return min(mi[BB[r - l + 1]][l],
             mi[BB[r - l + 1]][r - (1 << BB[r - l + 1]) + 1]);
}
int getma(int l, int r) {
  return max(ma[BB[r - l + 1]][l],
             ma[BB[r - l + 1]][r - (1 << BB[r - l + 1]) + 1]);
}
void init() {
  for (int j = (int)0; j <= (int)16; j++)
    for (int i = (int)(1 << j); i <= (int)(1 << (j + 1)) - 1; i++) BB[i] = j;
  for (int i = (int)1; i <= (int)n; i++) {
    mi[0][i] = ma[0][i] = a[i];
  }
  for (int j = (int)1; j <= (int)16; j++)
    for (int i = (int)1; i <= (int)n - (1 << j) + 1; i++) {
      mi[j][i] = min(mi[j - 1][i], mi[j - 1][i + (1 << (j - 1))]);
      ma[j][i] = max(ma[j - 1][i], ma[j - 1][i + (1 << (j - 1))]);
    }
}
bool f[N], g[N];
bool check(int S) {
  for (int i = (int)0; i <= (int)n; i++) f[i] = g[i] = 0;
  f[0] = g[0] = 1;
  int maf, mag;
  maf = mag = 0;
  for (int i = (int)0; i <= (int)n - 1; i++) {
    bool f1 = (i <= maf);
    bool f2 = (i <= mag);
    if (f1) {
      int now = a[i];
      if (i == 0) now = s1;
      int l = i + 1;
      int r = n;
      int rt = 0;
      while (l < r) {
        int mid = (l + r) >> 1;
        if ((abs(getma(i + 1, mid) - now) > S) ||
            (abs(getmi(i + 1, mid) - now) > S))
          r = mid;
        else
          l = mid + 1, rt = mid;
      }
      if (!(abs((getma(i + 1, l) - now) > S) ||
            (abs(getmi(i + 1, l) - now) > S)))
        rt = l;
      mag = max(mag, rt);
    }
    if (f2) {
      int now = a[i];
      if (i == 0) now = s2;
      int l = i + 1;
      int r = n;
      int rt = 0;
      while (l < r) {
        int mid = (l + r) >> 1;
        if ((abs(getma(i + 1, mid) - now) > S) ||
            (abs(getmi(i + 1, mid) - now) > S))
          r = mid;
        else
          l = mid + 1, rt = mid;
      }
      if (!((abs(getma(i + 1, l) - now) > S) ||
            (abs(getmi(i + 1, l) - now) > S)))
        rt = l;
      maf = max(maf, rt);
    }
  }
  return (maf == n) || (mag == n);
}
int main() {
  scanf("%d%d%d", &n, &s1, &s2);
  for (int i = (int)1; i <= (int)n; i++) scanf("%d", &a[i]);
  init();
  int L = abs(s1 - s2);
  int R = 1000000000;
  int ans = 0;
  while (L < R) {
    int mid = (L + R) >> 1;
    if (check(mid))
      ans = mid, R = mid;
    else
      L = mid + 1;
  }
  if (check(L)) ans = L;
  cout << ans << endl;
  return 0;
}
