n = int(eval(input()))

s, t = input().split()



list = []



for i in range(n):

    list.append(s[i])

    list.append(t[i])

    

print((''.join(list)))
n = int(eval(input()))

s, t = input().split()

list = []



for i in range(n):

    list += s[i]

    list += t[i]

    

print((''.join(list)))
n = int(eval(input()))
s, t = input().split()
list = []
for i in range(n):
    list.append(s[i])
    list.append(t[i])
print(("".join(list)))

n = int(eval(input()))
s, t = input().split()
list = []
for i in range(n):
    list += s[i]
    list += t[i]
print(("".join(list)))

-    list.append(s[i]) -    list.append(t[i]) +    list += s[i] +    list += t[i]