#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
long long dp[110][110][110];
int n, x;
char s[110];
long long phi[110];
long long pow_mod(long long a, long long e) {
  long long res = 1;
  for (; e; a = a * a % mod, e >>= 1)
    if (e & 1) res = res * a % mod;
  return res;
}
long long dfs(int dep, int l, int r) {
  if (dp[dep][l][r] != -1) return dp[dep][l][r];
  if (dep == 0) {
    if (l == r && s[l] == '0') return dp[dep][l][r] = 1;
    return dp[dep][l][r] = 0;
  }
  if (dep == 1) {
    if (l == r && s[l] == '1') return dp[dep][l][r] = 1;
    return dp[dep][l][r] = 0;
  }
  long long tmp1 = pow_mod(2, phi[dep - 2]), tmp2 = pow_mod(2, phi[dep - 1]);
  if (r != n) tmp1 = 1;
  if (l != 1) tmp2 = 1;
  long long res = (dfs(dep - 1, l, r) * tmp1 + dfs(dep - 2, l, r) * tmp2) % mod;
  for (int k = l; k < r; k++)
    res = (res + dfs(dep - 1, l, k) * dfs(dep - 2, k + 1, r)) % mod;
  return dp[dep][l][r] = res;
}
int main() {
  phi[0] = 1, phi[1] = 1;
  for (int i = 2; i <= 100; i++) phi[i] = (phi[i - 1] + phi[i - 2]) % (mod - 1);
  scanf("%d %d", &n, &x);
  scanf("%s", s + 1);
  memset(dp, -1, sizeof(dp));
  cout << dfs(x, 1, n) << endl;
  return 0;
}
