T = int(input())

def check(s):
    s0 = "helloworld"
    for i in range(10):
        if s[i] == "?" or s[i] == s0[i]:
            continue
        else:
            return False
    return "True"

def solve():
    N = int(input())
    S = input()
    T = "zzzz"
    for i in range(N - 9):
        if check(S[i:i + 10]):
            tmp = (S[:i] + "helloworld" + S[i + 10:]).replace("?", "a")
            T = min(T, tmp)
    if T == "zzzz":
        print(-1)
    else:
        print(T)

for _ in range(T):
    solve()