#include<iostream>
#include<algorithm>
#include<random>
#include<chrono>
#define pii pair<int,int>
using namespace std;
int main(){
    int n;
    cin>>n;
    int all[n];
    int pre=0;
    int cnt=1;
    int ans=1;
    int aa=0,bb=0;
    for(int i=0;i<n-1;i++){
        cin>>all[i];
        if(i==0){
            if(all[i]==0){
                cnt++;       
            }else{
                cnt=1;
            }
        }else {
            if(all[i]==0){
                cnt++;       
            }else{
                cnt=1;
            }
        }
        if(all[i]==0)aa++;
        else bb++;
        pre=all[i];
    }
    if(aa==n-1){
        cout<<n-1<<endl;
    }else if(bb==n-1){
        cout<<1<<endl;
    }else if(bb==n-2&&all[0]==0) {
        cout<<1<<endl;
    }else {
        cout<<max(2,cnt);
    }

    

    return 0;
}