import sys
input = sys.stdin.readline

N=int(input())

X=["a"]*N

S="bcdefghijklmnopqrstuvwxyz"

for i in range(N):
    A=[]
    for j in range(25):
        X[i]=S[j]
        print("?","".join(X),flush=True)
        ret=int(input())
        A.append(ret)

    if min(A)==max(A):
        X[i]="a"
    else:
        mind=A.index(max(A))
        X[i]=S[mind]

print("!","".join(X),flush=True)