MOD = 998244353

def main():
    import sys
    N, B, W = map(int, sys.stdin.readline().split())
    
    if B == 0:
        if W == 0:
            print(1)
        else:
            print(0)
        return
    
    S = W + 3 * B - N
    if S < 0 or S > 2:
        print(0)
        return
    
    from math import comb
    ans = 0
    
    # Case 1: t1 = 0, t2 = 0, S=0
    if S == 0:
        # All B black positions are between 2 and N-1
        # Available positions: M = N-2
        M = N - 2
        if M < B:
            pass
        else:
            ans = (ans + comb(M, B)) % MOD
    
    # Case 2: S=1, possible (t1, t2) = (0,1) or (1,0)
    if S == 1:
        # (t1, t2) = (0,1)
        # One black at N, others between 2 and N-1
        M = N - 2
        if (B - 1) <= M:
            ans = (ans + comb(M, B-1)) % MOD
        
        # (t1, t2) = (1, 0)
        M = N - 2
        if (B - 1) <= M:
            ans = (ans + comb(M, B-1)) % MOD
    
    # Case 3: S=2, (t1, t2)=(1,1)
    if S == 2:
        # Both 1 and N are selected
        if B < 2:
            pass
        else:
            M = N - 2
            if (B - 2) <= M:
                ans = (ans + comb(M, B-2)) % MOD
    
    print(ans % MOD)

if __name__ == "__main__":
    main()