#include<stdio.h>
#include<iostream>
#include<vector>
#include<cmath>
#include<algorithm>
#include<memory.h>
#include<map>
#include<set>
#include<queue>
#include<list>
#include<sstream>
#include<cstring>
#include<numeric>
using namespace std;

const int N = 1e5 + 3;
const int SZ = 5e7;
char buf[SZ];
int pos;
void * operator new (size_t x){
    pos += x;
if (pos > SZ)
throw 42;
return buf + pos - x;
}
void operator delete(void *x) { }
char s[N];

int main() {
    //freopen("input.txt", "r", stdin);
    int n;
    scanf("%d", &n);
    long long lastSuffix = 0;
    long long ans = 0;
    for (int j = 0; j < n; j++) {
        scanf("%s", s);

        long long maxBehind;
        long long c = 0;

        int len = strlen(s);


        vector<int> twos;
        for (int i = 0; i < len; i++) {
            if (s[i] == '2') {
                twos.push_back(i);
            }
        }

        if (twos.size() > 1) {
            for (int i = 1; i < twos.size() - 1; i++) {
                long long cur = twos[i] - twos[i - 1] + twos[i + 1] - twos[i] - 2;
                ans = max(cur, ans);
            }
        }


        int first = -1;
        int upTo = -1;
        for (int i = 0; i < len; i++) {
            if (s[i] == '2') {
                if(first == -1)
                    first = i;
                else {
                    upTo = i;
                    break;
                }
            }
        }
        if (first == -1) {
            lastSuffix += len;
            ans = max(lastSuffix, ans);
        }
        else if (upTo == -1) {
            lastSuffix += len - 1;
            ans = max(lastSuffix, ans);
        }
        else {
            lastSuffix += upTo - 1;
            ans = max(lastSuffix, ans);
            first = -1;
            int last = -1;
            for (int i = len - 1; i >= 0; i--) {
                if (s[i] == '2') {
                    if (first == -1) {
                        first = i;
                        last = i;
                    }
                    else {
                        last = i;
                        break;
                    }
                }
            }
            lastSuffix = len - last - 2;
            ans = max(ans, lastSuffix);
        }
    }
    printf("%lld", max(ans, lastSuffix));

    return 0;
}