#pragma GCC optimize ("O3") #pragma GCC target ("avx") #include using namespace std; typedef long long int ll; struct fastI{ char in[1<<26]; char const*o; fastI(){ o = in; in[fread(in,1,sizeof(in)-4,stdin)]=0; } fastI& operator>>(char& c){ while(*o&&*o<=32)++o; c=*o++; return *this; } fastI& operator>>(int& u){ u=0; unsigned s=0; while(*o&&*o<=32)++o; if (*o == '-')s = ~s, ++o; else if (*o == '+')++o; while('0'<=*o && *o<='9')u = (u<<3) + (u << 1) + (*o++ - '0'); (u^=s)+=!!s; return *this; } fastI& operator>>(long long& u){ u=0; uint64_t s=0; while(*o&&*o<=32)++o; if (*o == '-')s = ~s, ++o; else if (*o == '+')++o; while('0'<=*o && *o<='9')u = (u<<3) + (u << 1) + (*o++ - '0'); (u^=s)+=!!s; return *this; } } fin; constexpr ll mod=998244353; const int N=1024; ll dp[42][1024]; int main(){ int n,kk,x,y,a; fin >> n >> kk >> x >> y; vector A(N); int k=0; for(int i=0;i> a; if(!A[a]){ k++; A[a]=true; } } dp[0][0]=1; for(int i=0;i0))); } } ll res=0; for(int i=x;i<=min(1023,y);i++){ res+=dp[n][i]; } res%=mod; cout << res << endl; }