import sys
input = sys.stdin.readline

mod = 998244353
T = int(input())
for _ in range(T):
    N, M, L, R = map(int, input().split())
    ans = 0

    # d=0
    ans += R-L+1

    # d>0
    d1 = (L+N-2)//(N-1)
    d2 = R//(N-1)
    ans += (R-L+1)*(d1-1)+(R-(N-1)*d1+1 + R-(N-1)*d2+1)*(d2-d1+1)//2

    # d<0
    d1 = (M-R+N-2)//(N-1)
    d2 = (M-L+1)//(N-1)
    ans += (R-L+1)*(d1-1)+(M-L-(N-1)*d1+1 + M-L-(N-1)*d2+1)*(d2-d1+1)//2

    print(ans % mod)