from collections import deque
D=[]
N=int(input())
for i in range(N):
  D.append('a')
  
ans=[]
for i in range(N):
  C=[]
  for j in range(25):
    D[i]=chr(ord('a')+j) 
    c=''.join(D)
    print('?',c)
    s=int(input())
    C.append(s)
  D[i]=chr(ord('a')) 
  if len(set(C))==1:
    ans.append('z')
  else:
    ma=max(C)
    ans.append(chr(ord('a')+C.index(ma)))
print('!',''.join(ans))