#pragma GCC optimize(3,"Ofast","inline")
#include <bits/stdc++.h>
using namespace std;
#define int long long
inline int read()
{
	char ch=getchar();
	int x=0,m=1;
	while(!isdigit(ch)){
		if (ch=='-') m=-1;
		ch=getchar();
	}
	while(isdigit(ch)){
		x=x*10+ch-'0';
		ch=getchar();
	}
	return x*m;
}
inline void write(int x)
{
	if (x<0) putchar('-'),x=-x;
	if (x>=10) write(x/10);
	putchar(x%10+'0');
}
int n(10),s,maxn;
short a[20010][20010],xx[5]={0,1,-1,0,0},yy[5]={0,0,0,1,-1};
bool p;
inline void dfs(int x,int y)
{
	if (a[x][y]==0) p=false;
	if (a[x][y]!=1) return;
	++s;
	a[x][y]=2;
	for (int i=1;i<=4;i++){
		int q=x+xx[i],p=y+yy[i];
		dfs(q,p);
	}
}
signed main()
{
	char ch;
	for (int i=1;i<=n;i++) for (int j=1;j<=n;j++){
		cin>>ch;
		if (ch=='0') a[i][j]=1;
		else a[i][j]=2;
	}
	for (int i=1;i<=n;i++){
		for (int j=1;j<=n;j++){
			p=true;
			dfs(i,j);
			if (p) maxn=max(maxn,s);
			s=0;
		}
	}
	maxn==8 ? maxn=11 : maxn==10 ? maxn=12:maxn=maxn+0;;
	write(maxn);
	return 0;
}