#include <bits/stdc++.h>
#include <atcoder/all>

using namespace std;

//#define DISABLE_PRINT

#if defined(ENABLE_PRINT) && !defined(DISABLE_PRINT)

#define P(...) fprintf(stderr, __VA_ARGS__)
#define P2(fmt) fprintf(stderr, fmt)
#define LP fprintf(stderr, "L: %d\n", __LINE__)

#else

#define P(...) ((void)0)
#define P2(fmt) ((void)0)
#define LP ((void)0)

#endif

#define rep(i, n) for(int i = 0; i < (int)(n); ++i)
#define ALL(x) x.begin(),x.end()

using ll = long long;
using ull = unsigned long long;

int main(int, const char**)
{
    int N, M; cin >> N >> M;
    vector<bool> v(N);
    rep(i, N) {
        auto ti = i + 1;
        for(int j = 1; j * j <= ti; ++j) {
            if(ti % j != 0) continue;
            auto d = ti / j;
            v[j - 1] = !v[j - 1];
            if(j != d) {
                v[d - 1] = !v[d - 1];
            }
        }
    }

    vector<bool> act(N);
    rep(i, M) {
        int x; cin >> x;
        x--;
        act[x] = true;
    }

    int ans = 0;
    rep(i, N) {
        auto ti = N - i;
        if(v[ti - 1] == act[ti - 1]) continue;
        ans++;
        for(int j = 1; j * j <= ti; ++j) {
            if(ti % j != 0) continue;
            auto d = ti / j;
            v[d - 1] = !v[d - 1];
            if(d != j) {
                v[j - 1] = !v[j - 1];
            }
        }
    }

#if 0
    rep(i, N) {
        P("%d ", v[i] ? 1 : 0);
    }
    P("\n");
#endif    

    cout << ans << endl;
    return 0;
}