//Nguyen Huu Hoang Minh
#include <bits/stdc++.h>
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define reset(x) memset(x, 0,sizeof(x))
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define N 505
#define remain(x) if (x > MOD) x -= MOD
#define ii pair<int, int>
#define iiii pair< ii , ii >
#define viiii vector< iiii >
#define vi vector<int>
#define vii vector< ii >
#define bit(x, i) (((x) >> (i)) & 1)
#define Task "test"
#define int long long

using namespace std;

typedef long double ld;
const int inf = 1e10;
const int minf = -1e10;
const int Mod = 1e9+7;

int n;
string grid[N];
char arr[N][N*2];
int dp[2][N][N];

void readfile()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    if (fopen(Task".inp","r"))
    {
        freopen(Task".inp","r",stdin);
        //freopen(Task".out","w",stdout);
    }
}

void solve(){
    for(int i=0; i<n; i++) cin >> grid[i];
    memset(dp, 0, sizeof dp);
    for(int i=0; i<n; i++){
        for(int j=i; j<n; j++){
            arr[i][j] = grid[i][j-i];
 //           cout << arr[i][j] << ' ';
        }
        //cout << endl;
    }
    for(int i=0; i<n; i++){
        for(int j=0; j<n-i; j++){
            arr[i][j+n-1] = grid[i+j][n-i-1];
            //cout << arr[i][j+n-1] << ' ';
        }
        //cout << endl;
    }
    for(int i=0; i<n; i++) dp[0][i][i] = 1;
    for(int i=1; i<n; i++){
        for(int j=0; j<n-i; j++){
            for(int k=0; k<n-i; k++){
                if (arr[j][n-i-1]==arr[k][n+i-1]){
                    dp[i%2][j][k] = ( dp[(i+1)%2][j][k] + dp[(i+1)%2][j+1][k] + dp[(i+1)%2][j][k+1] + dp[(i+1)%2][j+1][k+1] )%Mod;
                }
                else dp[i%2][j][k] = 0;
            }
        }
    }
    cout << dp[(n-1)%2][0][0] << '\n';
}

void proc()
{
    while (cin >> n){
        if (!n) break;
        solve();
    }
}

signed main()
{
    readfile();
    proc();
    return 0;
}