N,X,Y = map(int,input().split())
m = min(X,Y)
M = max(X,Y)
dp = [0 for _ in range(N+1)]
dp[0] =1
dp[1] = 1
dp[2] = 1

mod = 998244353
for i in range(3,N):
    dp[i] += dp[i-1]
    if i - 3 >= 0:
        dp[i] += dp[i-3]
    dp[i] %= mod
n = M - m 
if m >= 2:
    n -=1
if M <= N -1:
    n -=1
print(dp[n])