#include <bits/stdc++.h>
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define FORR(i,a,b) for (int i=(a);i>=(b);i--)
#define pb push_back

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef set<int> si;
const int inf = 1e9;
const int mod = 1e9+7;
const int s = 80;
ll n, C, A[80];
ll a[s][s], b[s][s], c[s][s];

void merge(ll (&a1)[s][s], ll (&a2)[s][s]){
  FOR(i, 0, n){
    FOR(j, 0, n){
      ll d = 0;
      FOR(k, 0, n){
        d += a1[i][k] * a2[k][j] % mod;
      }
      c[i][j] = d % mod;
    }
  }
  FOR(i, 0, n){
    FOR(j, 0, n){
      a1[i][j] = c[i][j];
    }
  }
}
main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  cin >> n >> C;
  ll ans = 0;
  FOR(i, 0, n){
    b[i][i] = 1;
    cin >> A[i];
    FOR(j, i, n)a[i][j] = A[i];
  }
  while(C > 0){
    if(C & 1){
      merge(b, a);
    }
    merge(a, a);
    C >>= 1;
  }
  FOR(i, 0, n){
    ans += b[i][n-1] + mod - b[i][i];
    ans %= mod;
  }
  cout << ans << endl;
}