MOD = 998244353
def calc(n, X, Y):
    x = -(-X // n) * n
    y = Y // n * n
    if x > y:
        return (Y - X + 1) * Y // n
    else:
        tmp = (x - X) * x // n
        tmp += (Y - y + 1) * y // n
        tmp += n * (y - x) * (x + y - 1) // 2
        return tmp % MOD

def solve():
    N, M, L, R = map(int, input().split())
    N1 = N - 1
    ans = R - L + 1
    ans += calc(N - 1, L, R)
    ans += calc(N - 1, M - R, M - L)
    ans %= MOD
    print(ans)

T = int(input())
for t in range(T):
    solve()