mod = 998244353 omega = pow(3,119,mod) rev_omega = pow(omega,mod-2,mod) N = 2*10**5 g1 = [1]*(N+1) # 元テーブル g2 = [1]*(N+1) #逆元テーブル inv = [1]*(N+1) #逆元テーブル計算用テーブル for i in range( 2, N + 1 ): g1[i]=( ( g1[i-1] * i ) % mod ) inv[i]=( ( -inv[mod % i] * (mod//i) ) % mod ) g2[i]=( (g2[i-1] * inv[i]) % mod ) inv[0]=0 def _ntt(f,L,reverse=False): F=[f[i] for i in range(L)] n = L.bit_length() - 1 base = omega if reverse: base = rev_omega if not n: return F size = 2**n wj = pow(base,2**22,mod) res = [0]*2**n for i in range(n,0,-1): use_omega = pow(base,2**(22+i-n),mod) res = [0]*2**n size //= 2 w = 1 for j in range(0,L//2,size): for a in range(size): res[a+j] = (F[a+2*j] + w * F[a+size+2*j]) % mod t = (w * wj) % mod res[L//2+a+j] = (F[a+2*j] + t * F[a+size+2*j]) % mod w = (w * use_omega) % mod F = res return res def ntt(f,L=0): l = len(f) if not L: L = 1<<((l-1).bit_length()) while len(f) c[i] = sum(a[j] * b[i - j] for j in range(i + 1)) % 998244353. It returns an empty list if at least one of a and b are empty. Constraints ----------- > len(a) + len(b) <= 8388609 Complexity ---------- > O(n log n), where n = len(a) + len(b). """ n = len(a) m = len(b) if n == 0 or m == 0: return [] if min(n, m) <= 0: return _convolution_naive(a, b) if a is b: return _convolution_square(a) return _convolution_fft(a, b) import sys,random,bisect from collections import deque,defaultdict from heapq import heapify,heappop,heappush from itertools import permutations from math import log,gcd input = lambda :sys.stdin.readline() mi = lambda :map(int,input().split()) li = lambda :list(mi()) S = input() A,B,C = mi() a,b,c = S.count("a"),S.count("b"),S.count("c") A -= a; B-= b; C -= c; def make_f(a,A): f = [0 for i in range(A+1)] if a==0: f[0] = 1 else: for i in range(A+1): if i&1: f[i] = -g1[i+a-1]*g2[a-1] % mod else: f[i] = g1[i+a-1]*g2[a-1] % mod f[i] *= g1[A] * (g2[i] * g2[A-i] % mod) % mod f[i] %= mod return f f = make_f(a,A) g = make_f(b,B) h = make_f(c,C) res = convolution(f,convolution(g,h)) ans = 0 for i in range(len(res)): rest = A+B+C-i ans += res[i] * g1[rest+a+b+c+i] * g2[a+b+c+i] % mod ans %= mod ans *= g2[A] * g2[B] * g2[C] ans %= mod print(ans)