import sys

int1 = lambda x: int(x) - 1

# input = lambda: sys.stdin.buffer.readline()
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
i1 = lambda: int1(input())
mi = lambda: map(int, input().split())
mi1 = lambda: map(int1, input().split())
li = lambda: list(mi())
li1 = lambda: list(mi1())
lli = lambda n: [li() for _ in range(n)]

INF = float("inf")
# mod = int(1e9 + 7)
mod = 998244353

l, r = mi()
n = r - l + 1
a, b, c = mi()

sum_from_one_to_x = lambda x: x * (x + 1) // 2
sum_from_x_to_y = lambda x, y: sum_from_one_to_x(y) - sum_from_one_to_x(x - 1)
sqsum_from_one_to_x = lambda x: x * (x + 1) * (2 * x + 1) // 6
sqsum_from_x_to_y = lambda x, y: sqsum_from_one_to_x(y) - sqsum_from_one_to_x(x - 1)

ans = 0
if a + b < c:
    ans += max(n - (c + 1) + 1, 0) * (c - b - a + 1)
    ans += (n + a + b + 1) * sum_from_x_to_y(c + 2, n)
    ans += mod + max((n + 1) - (c + 2), 0) * (-n * (a + b) - (a + b)) % mod
    ans += mod - sqsum_from_x_to_y(c + 2, n) % mod
    ans %= mod
else:
    ans += (n + a + b + 1) * sum_from_x_to_y(a + b + 1, n)
    ans += mod + max((n + 1) - (a + b + 1), 0) * (-n * (a + b) - (a + b)) % mod
    ans += mod - sqsum_from_x_to_y(a + b + 1, n) % mod
    ans %= mod
print(ans)