I=input
P=998244353
u=(P+1)//2
for t in range(int(I())):
	N,M,L,R=map(int,I().split())
	N-=1
	a,b,c,d=R//N,-((M-L)//N),-((M-R)//N),L//N
	print((M*(c-b)+R*(a-c+1)+((d+b)*(d-b+1)-(a+c)*(a-c+1))*u*N-L*(d-b+1)+a-b+1)%P)