MOD = 998244353
l, r = map(int, input().split())
n = r - l
a, b, c = map(int, input().split())
c = max(c, a + b)
d = n - c + 1
e = c - (a + b) + 1
n -= c
if n < 0:
    print(0)
    exit()

ans = 0
ans -= n * (n + 1) * (2 * n + 1) // 6
ans += (d - e) * n * (n + 1) // 2
ans += d * e * (n + 1)
print(ans % MOD)
"""
for z in range(n - c + 1):
    ans += -z * z + (d - e) * z + d * e
    ans %= MOD
print(ans)
"""