#include <cstdio>#include <cstring>#include <algorithm>#define MX 55555#define lson l,m,n<<1#define rson m+1,r,n<<1|1#define lc n<<1#define rc n<<1|1using namespace std;int num[MX], ma[MX << 2], mi[MX << 2];int L, R, N, ans;inline void up(int n){ ma[n] = num[ma[lc]] > num[ma[rc]] ? ma[lc] : ma[rc]; mi[n] = num[mi[lc]] < num[mi[rc]] ? mi[lc] : mi[rc];}void B(int l = 1, int r = N, int n = 1){ if (l == r) { scanf("%d", &num[l]); ma[n] = mi[n] = l; return; } int m = l + r >> 1; B(lson), B(rson), up(n);}int QA(int l = 1, int r = N, int n = 1){ if (L <= l && r <= R) return ma[n]; int ans = 0, m = l + r >> 1, t; if (L <= m) t = QA(lson), ans = (num[ans] > num[t]) ? ans : t; if (m < R) t = QA(rson), ans = (num[ans] > num[t]) ? ans : t; return ans;}int QB(int l = 1, int r = N, int n = 1){ if (L <= l && r <= R) return mi[n]; int ans = N + 1, m = l + r >> 1, t; if (L <= m) t = QB(lson), ans = (num[ans] < num[t]) ? ans : t; if (m < R) t = QB(rson), ans = (num[ans] < num[t]) ? ans : t; return ans;}int S(int l, int r){ if (l >= r) return -1; L = l, R = r; int ans = -1, a = QA(), b = QB(); if (a > b) ans = max(a - b, max(S(l, b), S(a, r))); else ans = max(S(a + 1, b - 1), max(S(l, a), S(b, r))); return ans;}int main(){ while (~scanf("%d", &N)) { B(), num[N + 1] = 111111; printf("%dn", S(1, N)); } return 0;}
