#include<stdio.h>
#include<conio.h>

int main()
{
  FILE* f , *g;
  int nrbecuri,nrelevi;
  int* v;
  f=fopen("light2.in","rt");
  g=fopen("light2.out","wt");
  fscanf(f,"%i %i",&nrbecuri,&nrelevi);
  int i=0,j=0;
  v=(int*)malloc(sizeof(int)*nrelevi);
    
  while(i<nrelevi)
    {fscanf(f,"%i",v+i);
    i++;
    }

  int nrbecuriaprinse=0;
  i=0;
  while(i<nrbecuri)
    {int contor =0;
    for(j=0;j<nrelevi;j++)
      if(i%v[j]==0)
        contor++;
    if((contor%2)==0)
      nrbecuriaprinse++;  
    i++;
    }
  fprintf(g,"%i",nrbecuriaprinse);      
  fclose(g);    
  fclose(f);  
  //getch();
  return 0;    
}