#include
using namespace std;
long long int DP[20] = {0};
long long int count( int S[], int m, int n ){
if(DP[n])
return DP[n];
if(S[m-1] > n)
return 0;
if(n < 0)
return 0;
if(m<=0)
return 0;
return DP[n] = count(S, m-1, n) + count(S, m, n - S[m-1]);
}
int main(){
int n, m;
cin>>n>>m;
int S[m];
DP[0] = 1;
for(int i=0; i<m; i++)
cin>>S[i];
cout<<count(S, m, n);
return 0;
}