#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic pop
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;
using mint = modint1000000007;

mint dp[210][210][210];
const int di[] = {1, 0, -1, 0};
const int dj[] = {0, 1, 0, -1};

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int h, w;
  cin >> h >> w;
  vector<string> s(h);
  rep(i, h) cin >> s[i];
  if (s[0][0] != s[h - 1][w - 1]) {
    cout << 0 << '\n';
    return 0;
  }
  const int t = h + w - 2;
  dp[0][0][h-1] = 1;
  mint ans;
  rep(i, h) rep(j, w) {
    int s1 = i + j;
    int s2 = t - s1;
    if (s1 == s2) {
      ans += dp[i][j][i];
      break;
    } else if (s1 + 1 == s2) {
      ans += dp[i][j][i] + dp[i][j][i+1];
      break;
    } else if (s1 < s2) {
      rep(k, h) if (int l = s2 - k; 0 <= l && l < w) {
        rep(k1, 2) rep(k2, 2) {
          int ni = i + di[k1], nj = j + dj[k1];
          int nk = k - di[k2], nl = l - dj[k2];
          if (0 <= ni && ni < h && 0 <= nj && nj < w && 0 <= nk && nk < h && 0 <= nl && nl < w && s[ni][nj] == s[nk][nl]) {
            dp[ni][nj][nk] += dp[i][j][k];
          }
        }
      }
    }
  }
  cout << ans.val() << '\n';
}