int main()
{
int n; 
int sz[1000][1000];
int x1,y1;
int x2,y2;
int k,i;
int s;              //shengming
scanf("%d",&n);
for(k=0;k<n;k++){
for(i=0;i<n;i++)
scanf("%d",&(sz[k][i]));
}                    //??n*n??
for(k=0;k<n;k++){
for(i=0;i<n;i++){
if (sz[k][i]==0)
{x1=i;y1=k;break;}
}
}               //???????
for(k=n-1;k>=0;k--){
for(i=n-1;i>=0;i--){
if (sz[k][i]==0)
{x2=i;y2=k;break;}       //???????
}
}
s=(abs(x2-x1)-1)*(abs(y2-y1)-1);  //??255???
printf("%d",s);
return 0;
}