#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include <map>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <stack>
#include <algorithm>
#include <array>
#include <unordered_set>
#include <unordered_map>
#include <string>
using namespace std;

bool rcmp(int a, int b) { return a>b; }
typedef long long LL;


#define MOD 998244353
#define GGG 3
void assert(int *p) { *p=0; }

int expit(LL b, LL m) {
  LL r=1;
  while(m) {
    if (m&1) { r=r*b; r%=MOD; }
    b=b*b; b%=MOD;
    m>>=1;
  }
  return r;
}

void fft(int *p, int n, char revert) {
  if ((MOD-1)%n) assert(0);
  int rt = expit(GGG, (MOD-1)/n);
  LL x, y;
  if (revert) {
    rt = expit(rt, MOD-2);
  }
  int b, i, j, l, t;
  LL w, ww, v, u, vv;
  for (i=1, j=0; i<n; i++) {
    b=n>>1;
    for (; j&b; b>>=1) j^=b; j^=b;
    if (i<j) { t=p[i]; p[i]=p[j]; p[j]=t; }
  }
  for (l=2; l<=n; l<<=1) {
    w=rt;
    for (i=l; i<n; i<<=1) w=(w*w)%MOD;
    for (i=0; i<n; i+=l) {
      ww=1;
      for (j=0; j<l/2; j++) {
        u=p[i+j]; v=p[i+j+l/2]; v*=ww; v%=MOD;
        vv=u+v; if (vv>=MOD) vv-=MOD;
        p[i+j]=vv;
        vv=u-v; if (vv<0) vv+=MOD;
        p[i+j+l/2]=vv;
        ww*=w; ww%=MOD;
      }
    }
  }
  if (revert) {
    x = expit(n, MOD-2);
    for (i=0; i<n; i++) {
      vv=p[i]; vv*=x; vv%=MOD; p[i]=vv;
    }
  }
}

#define MAXN 1<<20
int pbuf1[MAXN];
int pbuf2[MAXN];
int mpoly(int *p1, int c1, int *p2, int c2) {
  int m=c1+c2+1;
  int n=1; while(n<m) n<<=1;
  int i;
  LL v;
  for (i=0; i<=c1; i++) pbuf1[i]=p1[i];
  for (; i<n; i++) pbuf1[i]=0;
  for (i=0; i<=c2; i++) pbuf2[i]=p2[i];
  for (; i<n; i++) pbuf2[i]=0;
  fft(pbuf1, n, 0);
  fft(pbuf2, n, 0);
  for (i=0; i<n; i++) { v=pbuf1[i]; v*=pbuf2[i]; v%=MOD; pbuf1[i]=v; }
  fft(pbuf1, n, 1);
  i=n-1; while(i>0&&pbuf1[i]==0) i--;
  return i;
}



int ft[100004];
int cs[100004];
int kcs[100004];
int ift[100004];
int pa[200004];
int pb[200004];
int main() {
    int n, i, m, mx, j, k, c;
    LL v, r;
    scanf("%d %d", &m, &n);
    ft[0]=ift[0]=1;
    for (i=1; i<=n; i++) {
        v=ft[i-1]; v*=i; v%=MOD;
        ft[i]=v;
        ift[i]=expit(v, MOD-2);
    }
    for (i=1; i<=m; i++) cs[i]=0;
    for (i=0; i<n; i++) {
        scanf("%d", &v);
        cs[v]++;
    }
    k=0; for (i=1; i<=m; i++) if (cs[i]) kcs[k++]=cs[i];
    mx = *max_element(kcs, kcs+k);
    for (i=0; i<mx; i++) pb[i]=0;
    for (; i<=n; i++) {
        v=1;
        for (j=0; j<k; j++) {
            c=kcs[j];
            // i!/(i-c)!
            v*=ft[i]; v%=MOD; 
            v*=ift[i-c]; v%=MOD;
        }
        v*=ift[i]; v%=MOD;
        pb[i]=v;
    }
    // for pa...
    for (i=0; i<=n; i++) {
        v=ift[i]; 
        if (i&1) {
            v=MOD-v; v%=MOD;
        }
        pa[i]=v;
    }
    mpoly(pa, n, pb, n);
    r=0;
    for (i=0; i<=n; i++) {
        v=pbuf1[i];
        v*=ft[i]; v%=MOD; r+=v; r%=MOD;
    }
    printf("%lld\n", r);
    return 0;
}