mod = 998244353

def f(x,n):
    # print(f"x = {x} n = {n}")
    if x < n-1:
        return 0

    first = x - (n-1) + 1

    ## y = -n * x + first

    last = first % (n-1)

    num = (first-last)//(n-1) + 1
    ans = (first+last)*num//2%mod
    # print(f"first = {first} last = {last} num = {num} ans = {ans}")
    return ans

def solve():

    n,m,l,r = map(int,input().split())
    ans = 0
    # dif = 0
    ans += (r-l+1)

    ans += f(r,n) - f(l-1,n)

    ans += f(m-l,n) - f(m-r-1,n)

    ans %= mod

    return ans


t = int(input())
for _ in range(t):
    print(solve())