#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------

ll L,R,A,B,C;
const ll mo=998244353;

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>L>>R;
	cin>>A>>B>>C;
	R-=L;
	
	if(R<C) {
		cout<<0<<endl;
		return;
	}
	R-=A+B;
	C-=A+B;
	__int128 v=R%mo;
	__int128 w=(v+3)*(v+2)*(v+1)/6;
	if(C>0) {
		// (x+1)*(R-x+1)=x^2+R*x+(R+1)
		__int128 a=(C-1)%mo;
		w-=a*(a+1)*(2*a+1)/6%mo;
		w-=(a*(a+1)/2)%mo*v%mo;
		w-=(a+1)*(v+1)%mo;
	}
	w=(w%mo+mo)%mo;
	cout<<(ll)w<<endl;
	
	
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}