hd2.cpp

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*/                              
#include<bits/stdc++.h>
using namespace std;
 
#define fastio ios_base::sync_with_stdio(0); cin.tie(0)
#define LL long long 
#define mod 1000000007 
#define all(v) v.begin(),v.end()
#define pr(v) pair<v,v>
#define pb push_back
#define FOR(i, j, k) for (auto i=j ; i<k ; i++)
#define ROF(i, j, k) for (auto i=j ; i>=k ; i--) 
#define debug(...) fprintf(stderr, __VA_ARGS__), fflush(stderr)
#define time__(d) for(long blockTime = 0; (blockTime == 0 ? (blockTime=clock()) != 0 : false); debug("%s time : %.4fs", d, (double)(clock() - blockTime) / CLOCKS_PER_SEC))

const long long INF = 1e18;
const long long MAX = 2e5+10;
int main(){
    fastio;
    int t=1;// cin>>t;
    while(t--){
        int n,m; cin>>m>>n;
        int a[n+1]; FOR(i,1,n+1) cin>>a[i];
        LL dp[m+1][n+1]; 
        FOR(i,0,m+1){
            FOR(j,0,n+1){
                if(i==0) dp[i][j]=1;
                else if(j==0) dp[i][j]=0;
                else {
                    dp[i][j] = dp[i][j-1];
                    if(i-a[j]>=0) dp[i][j] = dp[i][j] + dp[i-a[j]][j];
                }
            }
        }
        cout<<dp[m][n];
    }
}