import collections,sys,math,functools,operator,itertools,bisect,heapq,decimal,string,time,random
#sys.setrecursionlimit(10**9)
#n = int(input())
#alist = list(map(int,input().split()))
#alist = []
s = input()
t = input()
#n,m = map(int,input().split())
#for i in range(n):
#    alist.append(list(map(int,input().split())))
n = int(input())
for i in range(n):
    s += '_'
    s += t
print(s)