#include<iostream>
#include<algorithm>
#include<unordered_map>
using namespace std;
const int N = 1e5 + 10;
int f[N];
int main() {
int n;
cin >> n;
int res = 0;
for (int i = 1; i <= n; i++) {
cin >> f[i];
}
int i = 1, j = 1;
while (j <= n) {
unordered_map<int, int>mp;
int ans = 0;
for (j = i; j <= n; j++) {
if (mp[f[j]] != 0) {
break;
}
ans++;
mp[f[j]] = j;
}
res = max(res, ans);
i = mp[f[j]]+1;
}
cout << res;
}