#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
using namespace std;
int main()
{
freopen("input.inp", "r", stdin);
freopen("output.out", "w", stdout);
long long n;
long long x;
vector<long long> a;
map<long long, long long> d, d1;
cin >> n;
long long l = -1, r = -1, r1 = n, l1 = n;
for (long long i = 0; i < n; i++)
{
cin >> x;
a.push_back(x);
}
for (long long i = 0; i < n; i++)
{
d[a[i]]++;
if (d[a[i]] > 1)
{
l = i;
break;
}
}
for (long long i = n - 1; i >= 0; i--)
{
if (d[a[i]] >= 1)
{
r = i;
break;
}
d[a[i]]++;
}
for (long long i = n - 1; i >= 0; i--)
{
d1[a[i]]++;
if (d1[a[i]] > 1)
{
r1 = i;
break;
}
}
for (long long i = 0; i < n; i++)
{
if (d1[a[i]] >= 1)
{
l1 = i;
break;
}
d1[a[i]]++;
}
if (l == -1)
cout << 0;
else
{
cout << min(r - l + 1, r1 - l1 + 1);
}
}
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