Problem:
There are N participants in the CODE FESTIVAL 2016 Qualification contests. The participants are either students in Japan, students from overseas, or neither of these.  Only Japanese students or overseas students can pass the Qualification contests. The students pass when they satisfy the conditions listed below, from the top rank down. Participants who are not students cannot pass the Qualification contests.    * A Japanese student passes the Qualification contests if the number of the participants who have already definitively passed is currently fewer than A+B.   * An overseas student passes the Qualification contests if the number of the participants who have already definitively passed is currently fewer than A+B and the student ranks B-th or above among all overseas students.  A string S is assigned indicating attributes of all participants. If the i-th character of string S is `a`, this means the participant ranked i-th in the Qualification contests is a Japanese student; `b` means the participant ranked i-th is an overseas student; and `c` means the participant ranked i-th is neither of these.  Write a program that outputs for all the participants in descending rank either `Yes` if they passed the Qualification contests or `No` if they did not pass.

Incorrect submission (verdict: Wrong Answer):
def examA():
    S = SI(); N = len(S)
    T = "CODEFESTIVAL2016"
    ans = 0
    for i in range(N):
        if S[i]!=T[i]:
            ans +=1
    print(ans)
    return

def examB():
    N, A, B = LI()
    S = SI()
    d = defaultdict(int)
    for s in S:
        if s=="a":
            if d["a"]+d["b"]<A+B:
                print("YES")
                d[s] += 1
            else:
                print("NO")
        elif s=="b":
            if d["a"]+d["b"]<A+B and d["b"]<B:
                print("YES")
                d[s] += 1
            else:
                print("NO")
        else:
            print("NO")
    return

def examC():
    return

import sys,copy,bisect,itertools,heapq,math
from heapq import heappop,heappush,heapify
from collections import Counter,defaultdict,deque
def I(): return int(sys.stdin.readline())
def LI(): return list(map(int,sys.stdin.readline().split()))
def LSI(): return list(map(str,sys.stdin.readline().split()))
def LS(): return sys.stdin.readline().split()
def SI(): return sys.stdin.readline().strip()
global mod,mod2,inf,alphabet,ALPHABET, _ep
mod = 10**9 + 7
mod2 = 998244353
inf = 10**18
_ep = 1e-9
alphabet = [chr(ord('a') + i) for i in range(26)]
ALPHABET = [chr(ord('A') + i) for i in range(26)]

if __name__ == '__main__':
    examB()


Fixed, accepted submission:
def examA():
    S = SI(); N = len(S)
    T = "CODEFESTIVAL2016"
    ans = 0
    for i in range(N):
        if S[i]!=T[i]:
            ans +=1
    print(ans)
    return

def examB():
    N, A, B = LI()
    S = SI()
    d = defaultdict(int)
    for s in S:
        if s=="a":
            if d["a"]+d["b"]<A+B:
                print("Yes")
                d[s] += 1
            else:
                print("No")
        elif s=="b":
            if d["a"]+d["b"]<A+B and d["b"]<B:
                print("Yes")
                d[s] += 1
            else:
                print("No")
        else:
            print("No")
    return

def examC():

    return

import sys,copy,bisect,itertools,heapq,math
from heapq import heappop,heappush,heapify
from collections import Counter,defaultdict,deque
def I(): return int(sys.stdin.readline())
def LI(): return list(map(int,sys.stdin.readline().split()))
def LSI(): return list(map(str,sys.stdin.readline().split()))
def LS(): return sys.stdin.readline().split()
def SI(): return sys.stdin.readline().strip()
global mod,mod2,inf,alphabet,ALPHABET, _ep
mod = 10**9 + 7
mod2 = 998244353
inf = 10**18
_ep = 1e-9
alphabet = [chr(ord('a') + i) for i in range(26)]
ALPHABET = [chr(ord('A') + i) for i in range(26)]

if __name__ == '__main__':
    examB()