// C++ 14
#include <iostream>
#include <string>
#include <vector>
#include <list>
#include <algorithm>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <unordered_map>
#include <math.h>

#define ll long long
#define Int ll
#define loop(__x, __start, __end) for(Int __x = __start; __x < __end; __x++)
#define loopdown(__x, __start, __end) for(Int __x = __start; __x > __end; __x--)
#define rep(__n) for(Int __x = 0; __x < __n; __x++)
#define span(__a,__x,__y) __a.begin()+__x,__a.begin()+__y
#define span_all(__a) __a.begin(),__a.end()
#define len(__x) (__x.size())
#define last(__x) (__x[__x.size()-1])

using namespace std;

struct Point {
  Int x, y;
  Point(Int x, Int y): x(x), y(y) {}
  Point(): x(0), y(0) {}

  Point operator + (Point v) { return Point(x + v.x, y + v.y); }
  Point operator - (Point v) { return Point(x - v.x, y - v.y); }
  bool operator == (const Point &v) const {
    return x == v.x && y == v.y;
  }
  bool operator< (const Point &p1) const {
    return x < p1.x && y < p1.y;
  }
};
ostream & operator << (ostream & out, Point const & v) {
  out << "Point(" << v.x << ", " << v.y << ')';
  return out;
}

istream & operator >> (istream & in, Point & v) {
  Int x, y;
  in >> x; in >> y; v.x = x; v.y = y;
  return in;
}

// Geometry

#define EPS 0.0000000001

class Vector2 {
public:
  double x, y;
  
  Vector2(double x = 0, double y = 0): x(x), y(y) {}
  
  Vector2 operator + (Vector2 v) { return Vector2(x + v.x, y + v.y); }
  Vector2 operator - (Vector2 v) { return Vector2(x - v.x, y - v.y); }
  Vector2 operator * (double k) { return Vector2(x * k, y * k); }
  Vector2 operator / (double k) { return Vector2(x / k, y / k); }
  
  double length() { return sqrt(norm()); }
  double norm() { return x * x + y * y; }
  double dot (Vector2 v) { return x * v.x + y * v.y; }
  double cross (Vector2 v) { return x * v.y - y * v.x; }
  
  bool operator < (const Vector2 &v) const {
    return x != v.x ? x < v.x : y < v.y;
  }
  
  bool operator == (const Vector2 &v) const {
    return fabs(x - v.x) < EPS && fabs(y - v.y) < EPS;
  }
};

ostream & operator << (ostream & out, Vector2 const & v) { 
  out<< "Vector2(" << v.x << ", " << v.y << ')';
  return out;
}

istream & operator >> (istream & in, Vector2 & v) { 
  double x, y;
  in >> x;
  in >> y;
  v.x = x;
  v.y = y;
  return in;
}

const Int MAX_N = 50001;
const Int MAX_M = 21;
const Int MAX_V = 10001;
const Int INFTY = 50010;
Int N, M;
vector<Int> coins;

void input() {
  cin >> N >> M;
  Int coin;
  rep(M) {
    cin >> coin;
    coins.push_back(coin);
  }
}

// WA: 15 = 12 + 2 + 1 よりも 15 = 8 + 7 が優秀
Int greedy() {
  sort(span_all(coins));
  reverse(span_all(coins));
  Int count = 0;
  Int left = N;
  for (auto x: coins) {
    if (x > left) continue;
    count += (left / x);
    left -= (left / x) * x;
  }
  return count;
}

vector<vector<Int> > dp(MAX_M, vector<Int>(MAX_N, -1));

Int solveRec(Int m, Int amount) {
  if (m == M-1) return amount; // The last coin is "1"
  if (amount == 0) return 0;
  Int &cache = dp.at(m).at(amount);
  if (~cache) return cache;
  Int coin = coins.at(m);
  // i) use or not use
  Int min_count = solveRec(m+1, amount);
  if (coin <= amount) {
    min_count = min(min_count, 1 + solveRec(m, amount - coin));
    min_count = min(min_count, 1 + solveRec(m+1, amount - coin));
  }
  cache = min_count;
  return min_count;
}

void solve() {
  sort(span_all(coins));
  reverse(span_all(coins));
  cout << solveRec(0, N) << endl;
}

int main() {
  input();
  solve();
  return 0;
}



Measured memory_bytes: 12740