#include <fstream>

using namespace std;

ifstream fin("light2.in");
ofstream fout("light2.out");

typedef long long i64;

const int kmax= 22;

i64 n, sol;
int k;
int v[kmax+1];

i64 gcd( i64 x, i64 y ) {
     if ( y==0 )
          return x;
     return gcd(y, x%y);
}

void backt( int x, int nr, i64 aux ) {
     if ( x==k+1 ) {
          if ( nr%2==0 && nr>0 ) {
               sol= sol-n/aux*(1<<(nr-1));
          } else if ( nr%2==1 ) {
               sol= sol+n/aux*(1<<(nr-1));
          }
     } else {
          backt(x+1, nr, aux);

          i64 cmmmc= (i64)aux/gcd(aux, v[x])*v[x];
          if ( cmmmc<=n ) {
               backt(x+1, nr+1, cmmmc);
          }
     }
}

int main(  ) {
     fin>>n>>k;
     for ( int i= 1; i<=k; ++i ) {
          fin>>v[i];
     }

     backt(1, 0, 1);

     fout<<sol<<"\n";

     return 0;
}