C++ :

#include<cstdio>
#include<stack>
#include<cstring>

#define MIN(a,b) ((a)<(b)?(a):(b))
#define MAXN 2010

using namespace std;

int n,b[MAXN],tot,dfn[MAXN],low[MAXN],timeclock,block,belong[MAXN],w[MAXN],tans,ind[MAXN],bb[MAXN];
int f[MAXN][MAXN];
bool flag[MAXN][MAXN],vis[MAXN],insta[MAXN];
stack <int> sta;

struct at{
	int x,y,last,nex;
}a[2*MAXN*MAXN];

void add(int x,int y)
{
	tot++;
	a[tot].x=x;
	a[tot].y=y;
	a[tot].last=b[x];
	a[tot].nex=bb[y];
	bb[y]=tot;
	b[x]=tot;
}

void dfs(int x)
{
	dfn[x]=low[x]=++timeclock;
	sta.push(x);insta[x]=1;
	for(int i=b[x];i;i=a[i].last){
		if(!dfn[a[i].y]){
			dfs(a[i].y);
			low[x]=MIN(low[x],low[a[i].y]);
		}else{
			if(insta[a[i].y]){
				low[x]=MIN(low[x],low[a[i].y]);
			}
		}
	}
	if(low[x]==dfn[x]){
		int now;
		block++;
		do{
			now=sta.top();
			sta.pop();insta[now]=0;
			belong[now]=block;
			w[block]++;
		}while(now!=x);
	}
}

void Dfs(int x)
{
	tans+=w[x];
	vis[x]=1;
	for(int i=b[x];i;i=a[i].last){
		if(!vis[a[i].y])
			Dfs(a[i].y);
	}
	return ;
}

int main()
{
	//freopen("connect.in","r",stdin);
	//freopen("connect.out","w",stdout);
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			int x=0;
			scanf("%1d",&x);
			if(x==1)	add(i,j);
		}
	}
	for(int i=1;i<=n;i++){
		if(!dfn[i]){
			dfs(i);
		}
	}
	memset(b,0,sizeof(b));
	memset(bb,0,sizeof(bb));
	int t=tot;
	for(int i=1;i<=t;i++){
		int u=a[i].x,v=a[i].y;
		if(belong[u]!=belong[v]&&!flag[belong[u]][belong[v]]){
			add(belong[u],belong[v]);
			flag[belong[u]][belong[v]]=1;
			ind[belong[v]]++;
			//printf("%d -> %d \n",belong[u],belong[v]);
		}
	}
	long long ans=0;
	for(int i=1;i<=block;i++){
		for(int j=1;j<=block;j++){
			if(ind[j]==0){
				sta.push(j);
				ind[j]--;
				for(int k=b[j];k;k=a[k].last){
					ind[a[k].y]--;
				}
				break;
			}
		}
	}
	while(!sta.empty()){
		int x=sta.top();sta.pop();
		f[x][x/30]|=1<<(x%30);
		for(int i=bb[x];i;i=a[i].nex){
			int y=a[i].x;
			for(int j=0;j<(block/30+1);j++)
				f[y][j]|=f[x][j];
		}
	}
	for(int i=1;i<=block;i++){
		int ww=0;
		for(int j=1;j<=block;j++){
			if(f[i][j/30]&1<<(j%30))
				ww+=w[j];
		}
		ans+=ww*w[i];
	}
	printf("%lld",ans);
	getchar();getchar();
	return 0;
}