K=int(input())
S=input()

def moji(S,K):
    if len(S)<=K:
        print(S)
    else:
        T=""
        for i in range(len(S)):
            if i <K:
                 T+=S[i]
            if i >=K:
                continue
        T+="..."
        print(T)

moji(S,K)