#include <bits/stdc++.h>
using namespace std;
long long n, x, f[105][105][105], t[105];
char s[105];
long long q_pow(long long a, long long b) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = ans * a % (1000000007);
    a = a * a % (1000000007);
    b >>= 1;
  }
  return ans;
}
int main() {
  long long i, j, l, r;
  scanf("%lld%lld", &n, &x);
  scanf("%s", s + 1);
  t[0] = 1;
  t[1] = 1;
  for (i = 2; i <= x; i++) t[i] = (t[i - 1] + t[i - 2]) % ((1000000007) - 1);
  for (i = 0; i <= x; i++) t[i] = q_pow(2, t[i]);
  for (i = 1; i <= n; i++) f[s[i] == '1'][i][i] = 1;
  for (i = 2; i <= x; i++) {
    for (l = 1; l <= n; l++) {
      for (r = l; r <= n; r++) {
        if (l == 1)
          f[i][l][r] = (f[i][l][r] + f[i - 2][l][r] * t[i - 1] % (1000000007)) %
                       (1000000007);
        else
          f[i][l][r] = (f[i][l][r] + f[i - 2][l][r]) % (1000000007);
        if (r == n)
          f[i][l][r] = (f[i][l][r] + f[i - 1][l][r] * t[i - 2] % (1000000007)) %
                       (1000000007);
        else
          f[i][l][r] = (f[i][l][r] + f[i - 1][l][r]) % (1000000007);
        for (j = l; j < r; j++)
          f[i][l][r] = (f[i][l][r] +
                        f[i - 1][l][j] * f[i - 2][j + 1][r] % (1000000007)) %
                       (1000000007);
      }
    }
  }
  printf("%lld\n", f[x][1][n]);
  return 0;
}
