import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################
def f(a, b, l, r):
    F = lambda x:a * (x + 1) * x //2 + b * x
    return F(a) - F(b)

mod = 998244353
for _ in range(ni()):
    n,m,l,r = na()
    ans = (r-l+1)
    # d = [1, (m-r)//(n-1)]
    ans += (m-r)//(n-1) * (r - l + 1)
    # d = [(m-r)/(n-1)+1, m//(n-1)]
    ans += f(-(n-1), m, (m-r)//(n-1), m//(n-1)) - (m//(n-1)-(m-r)//(n-1)) * (l)
    ans += l // (n-1) * (r - l + 1)
    ans += (r//(n-1) - l//(n-1)) * (r+1)-f(-(n-1), m, l//(n-1), r//(n-1))
    print(ans%mod)
#