import std.conv, std.functional, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.container, std.math, std.numeric, std.range, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


enum LIM = 10^^4 + 10;

bool[] isnp;

void prepare() {
  isnp = new bool[LIM];
  foreach (i; 2 .. LIM) {
    if (!isnp[i]) {
      for (int j = 2 * i; j < LIM; j += i) {
        isnp[j] = true;
      }
    }
  }
}

int M;
int N;
int[] C;

void main() {
  prepare();
  
  try {
    for (; ; ) {
      M = readInt();
      N = readInt();
      C = new int[N];
      foreach (i; 0 .. N) {
        C[i] = readInt();
      }
      
      auto dp = new int[M + 1];
      dp[] = -1;
      dp[0] = 0;
      foreach (i; 0 .. N) {
        foreach (x; C[i] .. M + 1) {
          if (dp[x - C[i]] >= 0) {
            chmax(dp[x], dp[x - C[i]] + 1);
          }
        }
      }
      
      int ans = dp.maxElement;
      foreach (x; 2 .. M) {
        if (!isnp[x]) {
          if (dp[M - x] >= 0) {
            ans += dp[M - x];
          }
        }
      }
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}