#include <iostream>
#include <cstdio>
#include<vector>
using namespace std;
char arr[2001][2001];
int main(void) {
unsigned long int n;
unsigned long int i,j,k;
scanf("%lu",&n);
vector<int>adj[n];
for(i=0;i<n;i++)
{
scanf("%s",arr[i]);
for(j=0;j<n;j++)
{
if(arr[i][j]=='1')
{
adj[i].push_back(j);
}
}
}
long int count=0;
unsigned int p,q;
for(i=0;i<n;i++)
{
for(j=0;j<adj[i].size();j++)
{
{
for(k=j+1;k<adj[i].size();k++)
{
{
p=adj[i][j];
q=adj[i][k];
if(arr[p][q]=='0')
{
arr[p][q]=arr[q][p]='2';
count++;
}
}
}
}
}
}
printf("%ld\n",2*count);
return 0;
}
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