int main()
{
int a[100][100];
int x1, y1, x2, y2, area=0;
int n, i, j;
/* ??n*n?? */
scanf("%d",&n);
for (i=0; i<n; i++) {
for (j=0; j<n; j++) {
scanf("%d", &a[i][j]);
}
}
/* ?????? */
for (i=0; i<n; i++) {
for (j=0; j<n; j++) {
/* ??????0???????? */
if (a[i][j] == 0) {
x1=i;
y1=j;
break;
}
}
if (j<n) {
break;
}
}
/* ?????? */
for (i=n-1; i>=0; i--) {
for (j=n-1; j>=0; j--) {
/* ??????0???????? */
if (a[i][j] == 0) {
x2=i;
y2=j;
break;
}
}
if (j>=0) {
break;
}
}
/* ??????????? */
area=(x2-x1-1)*(y2-y1-1);
printf("%d", area);
return 0;
}
