maxpair

#include <bits/stdc++.h>
#define TASK "TESTCODE"
using namespace std;
const int N = 1e5;
int index[N + 1], n, a[N + 1], res = 0;
void read()
{
    cin >> n;
    for (int i = 1; i <= n; ++ i)
    {
        cin >> a[i];
        index[a[i]] = i;
    }
}
void solve()
{
    index[0] = 1e9;
    for (int i = 1; i <= n; ++ i)
    {
        res = max(res, index[i] - index[i - 1]);
        index[i] = min(index[i], index[i - 1]);
    }
    cout << res;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    //freopen(TASK".INP", "r", stdin);
    //freopen(TASK".OUT", "w", stdout);
    int t = 1;
    bool typetest = false;
    if (typetest)
    {
        cin >> t;
    }
    for (int __ = 1; __ <= t; ++ __)
    {
        read();
        solve();
    }
}