import sys,random,bisect
from collections import deque,defaultdict,Counter
from heapq import heapify,heappop,heappush
from itertools import cycle, permutations
from math import log,gcd

input = lambda :sys.stdin.readline().rstrip()
mi = lambda :map(int,input().split())
li = lambda :list(mi())

N,X,Y = mi()
S = input()

A = []
i = 0
while i < N:
    if S[i:i+3]=="con":
        a = 1
        j = i+3
        while j+2 < len(S):
            if S[j:j+3]=="con":
                a += 1
                j += 3
            else:
                break
        A.append(a)
        i = j
    else:
        i += 1

res = 0
dp = [-1] * ((N//3)*2+10)
dp[0] = 0
for a in A:
    ndp = [-1] * ((N//3)*2)
    for s in range(-N//3,N//3+1):
        if dp[s] == -1:
            continue
        t = dp[s]
        for k in range(a//X+1):
            x = k
            y = (a-k*X)//Y
            ndp[s+x-y] = max(ndp[s+x-y],t+x+y)
    dp = ndp

for s in range(-N//3,2):
    if dp[s]!=-1:
        if s <= 0:
            tmp = dp[s] + s
        else:
            tmp = dp[s]
        res = max(res,tmp)

print(res)