#include <bits/stdc++.h>
template <class T = int>
inline T readInt();
inline double readDouble();
inline int readUInt();
inline int readChar();
inline void readWord(char *s);
inline bool readLine(char *s);
inline bool isEof();
inline int getChar();
inline int peekChar();
inline bool seekEof();
inline void skipBlanks();
template <class T>
inline void writeInt(T x, char end = 0, int len = -1);
inline void writeChar(int x);
inline void writeWord(const char *s);
inline void writeDouble(double x, int len = 0);
inline void flush();
static struct buffer_flusher_t {
  ~buffer_flusher_t() { flush(); }
} buffer_flusher;
static const int buf_size = 4096;
static unsigned char buf[buf_size];
static int buf_len = 0, buf_pos = 0;
inline bool isEof() {
  if (buf_pos == buf_len) {
    buf_pos = 0, buf_len = fread(buf, 1, buf_size, stdin);
    if (buf_pos == buf_len) return 1;
  }
  return 0;
}
inline int getChar() { return isEof() ? -1 : buf[buf_pos++]; }
inline int peekChar() { return isEof() ? -1 : buf[buf_pos]; }
inline bool seekEof() {
  int c;
  while ((c = peekChar()) != -1 && c <= 32) buf_pos++;
  return c == -1;
}
inline void skipBlanks() {
  while (!isEof() && buf[buf_pos] <= 32U) buf_pos++;
}
inline int readChar() {
  int c = getChar();
  while (c != -1 && c <= 32) c = getChar();
  return c;
}
inline int readUInt() {
  int c = readChar(), x = 0;
  while ('0' <= c && c <= '9') x = x * 10 + c - '0', c = getChar();
  return x;
}
template <class T>
inline T readInt() {
  int s = 1, c = readChar();
  T x = 0;
  if (c == '-')
    s = -1, c = getChar();
  else if (c == '+')
    c = getChar();
  while ('0' <= c && c <= '9') x = x * 10 + c - '0', c = getChar();
  return s == 1 ? x : -x;
}
inline double readDouble() {
  int s = 1, c = readChar();
  double x = 0;
  if (c == '-') s = -1, c = getChar();
  while ('0' <= c && c <= '9') x = x * 10 + c - '0', c = getChar();
  if (c == '.') {
    c = getChar();
    double coef = 1;
    while ('0' <= c && c <= '9') x += (c - '0') * (coef *= 1e-1), c = getChar();
  }
  return s == 1 ? x : -x;
}
inline void readWord(char *s) {
  int c = readChar();
  while (c > 32) *s++ = c, c = getChar();
  *s = 0;
}
inline bool readLine(char *s) {
  int c = getChar();
  while (c != '\n' && c != -1) *s++ = c, c = getChar();
  *s = 0;
  return c != -1;
}
static int write_buf_pos = 0;
static char write_buf[buf_size];
inline void writeChar(int x) {
  if (write_buf_pos == buf_size)
    fwrite(write_buf, 1, buf_size, stdout), write_buf_pos = 0;
  write_buf[write_buf_pos++] = x;
}
inline void flush() {
  if (write_buf_pos) {
    fwrite(write_buf, 1, write_buf_pos, stdout), write_buf_pos = 0;
    fflush(stdout);
  }
}
template <class T>
inline void writeInt(T x, char end, int output_len) {
  if (x < 0) writeChar('-'), x = -x;
  char s[24];
  int n = 0;
  while (x || !n) s[n++] = '0' + x % 10, x /= 10;
  while (n < output_len) s[n++] = '0';
  while (n--) writeChar(s[n]);
  if (end) writeChar(end);
}
inline void writeWord(const char *s) {
  while (*s) writeChar(*s++);
}
inline void writeDouble(double x, int output_len) {
  if (x < 0) writeChar('-'), x = -x;
  int t = (int)x;
  writeInt(t), x -= t;
  writeChar('.');
  for (int i = output_len - 1; i > 0; i--) {
    x *= 10;
    t = std::min(9, (int)x);
    writeChar('0' + t), x -= t;
  }
  x *= 10;
  t = std::min(9, (int)(x + 0.5));
  writeChar('0' + t);
}
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4")
using namespace std;
mt19937 Random(time(0));
const long long INF = 1e9 + 10;
const long long MOD = 1e9 + 7;
const long long P = 239017;
const long long BINF = 1e18 + 10;
const long long N = 1e5 + 10;
long long fact[N], in[N];
void add(long long &a, long long b) {
  a += b;
  if (a >= MOD) {
    a -= MOD;
  }
}
long long mult(long long a, long long b) { return (a * b) % MOD; }
long long C(long long n, long long k) {
  if (k > n) {
    return 0;
  }
  return mult(mult(fact[n], in[k]), in[n - k]);
}
long long b_pow(long long a, long long b) {
  if (!b) {
    return 1;
  }
  if (b & 1) {
    return (a * b_pow(a, b - 1)) % MOD;
  }
  long long c = b_pow(a, b >> 1);
  return (c * c) % MOD;
}
long long inv(long long x) { return b_pow(x, MOD - 2); }
bool check(long long x) {
  while (x) {
    long long last = x % 10;
    if (last != 4 && last != 7) {
      return false;
    }
    x /= 10;
  }
  return true;
}
void source() {
  fact[0] = 1;
  in[0] = inv(1);
  for (long long i = 1; i <= 1e5; i++) {
    fact[i] = mult(fact[i - 1], i);
    in[i] = inv(fact[i]);
  }
  long long n = readInt(), k = readInt(), other = 0;
  unordered_map<long long, long long> cnt;
  for (long long i = 0; i < n; i++) {
    long long x = readInt();
    if (check(x)) {
      cnt[x]++;
    } else {
      other++;
    }
  }
  vector<long long> dp(k + 1);
  dp[0] = 1;
  for (auto it : cnt) {
    for (long long i = k - 1; i >= 0; i--) {
      add(dp[i + 1], mult(dp[i], it.second));
    }
  }
  long long ans = 0;
  for (long long i = 0; i <= k; i++) {
    add(ans, mult(dp[i], C(other, k - i)));
  }
  writeInt(ans);
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  source();
  return 0;
}
