ll N,M,A,B,S,T;
{
	mint V[2d5],R[2d5],X;
	rd(N,M);
	V[0]=R[0]=T=1;
	rep(N){
		rd(A);
		RREP(i,S+=A)V[i+A]+=V[i];
	}
	rep(M){
		rd(B);
		RREP(i,T+=B)R[i+B]+=R[i];
	}
	rd(A,B);
	V[1..S]+=V[0..];
	rep(i,1,T)X+=R[i]*=V[min(B*i,S)]-V[min(A*i-1,S)];
	wt(X);
}