n,a,b=map(int,input().split())
N=n
s=["#"]+list(input())
x=[]
l=1
nod=["o","n","c"]
while l<=n:
    if s[l]!="c":l+=1
    else:
        r=l
        while r<n:
            d=(r-l)%3
            if s[r+1]==nod[d]:
                r+=1
            else:
                break
        num=(r-l+1)//3
        if num>0:x.append(num)
        l=r+1
n=len(x)
if n==0:
    print(0)
    exit()

dp=[-2**60]*(N//3+10)

dp[0]=0
for i in range(n):
    newdp=[-2**60]*(N//3+10)
    for j in range(len(dp)):
        if dp[j]<0:break
        for k in range(10**9):
            if a*k>x[i]:break
            newdp[j+k]=max(newdp[j+k],dp[j]+(x[i]-a*k)//b)
    dp=newdp[:]
ans=0
for A in range(len(dp)):
    if A>dp[A]:
        ans=max(ans,2*dp[A]+1)
    else:
        ans=max(ans,2*A)
print(ans)