#include <bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
int32_t main(){
cin.tie(nullptr)->sync_with_stdio(0);
int n;
cin >> n;
vector<bool> dp(n+2,false);
priority_queue<pii> pq;
for(int i = 1; i <= n; i++){
int x;
cin >> x;
pq.push({x,i});
}
int cur = 0, ans = 0;
while(!pq.empty()){
auto [x,i] = pq.top();
pq.pop();
if(x == 0) break;
if(dp[i - 1] && dp[i + 1]){
cur--;
dp[i] = 1;
}else if(dp[i-1] || dp[i +1]){
dp[i] = 1;
}else{
dp[i] = 1;
cur++;
}
// ans = max(ans,cur);
// pii temp;
while(!pq.empty() && pq.top().first == x){
auto [k,idx] = pq.top();
pq.pop();
if(dp[idx - 1] && dp[idx + 1]){
cur--;
dp[idx] = 1;
}else if(dp[idx-1] || dp[idx +1]){
dp[idx] = 1;
}else{
dp[idx] = 1;
cur++;
}
}
// cout << cur << '\n';
ans = max(ans,cur);
}
cout << ans;
}
