def triple_dot():
    k = int(input())
    s = input()
    len_s =len(s)
    result_s = []
    
    if len_s > k:
        for i in range(k):
            result_s.append(s[i])
        print("".join(result_s) + "...")
    if len_s <= k:
        print("".join(s))

triple_dot()