def floor_sum(n, m, a, b):
    ans = 0
    while True:
        if a >= m or a < 0:
            ans += n * (n - 1) * (a // m) // 2
            a %= m
        if b >= m or b < 0:
            ans += n * (b // m)
            b %= m
        y_max = a * n + b
        if y_max < m: break
        n, b, m, a = y_max // m, y_max % m, a, m
    return ans  

mod = 998244353

def naive_fs(n, m, a, b):
    ans = 0
    for x in range(0, n):
        ans += (a*x+b)//m

    return ans

t = int(input())

for _ in range(t):
    n, m, l, r = map(int, input().split())
    n -= 1
    ans = floor_sum(m + 1, n, -1, r+m*n) - floor_sum(m + 1, n, -1, l - 1 + m*n)
    ans %= mod
    print(ans)