def f(L):
  if L < 0:
    return 0
  return (L+1)*(L+2)*(L+3)//6%998244353

L,R = map(int, input().split())
A,B,C = map(int, input().split())
N = R-L
if A+B >= C:
  print(f(N-A-B))
  exit()

C -= A+B
N -= A+B

if N < C:
  print(0)
else:
  print((f(N)-f(C-1)-C*(C+1)*(N-C+1)//2)%998244353)