import sys

# sys.setrecursionlimit(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()

# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = (1 << 63)-1
# inf = (1 << 31)-1
# md = 10**9+7
md = 998244353

t = "helloworld"
def solve():
    def ok(si):
        if n-si < 10: return False
        for i, c in enumerate(t):
            if s[si+i] == "?": continue
            if s[si+i] != c: return False
        return True

    n = II()
    s = SI()

    if t in s:
        s=s.replace("?","a")
        print(s)
        return

    s=list(s)
    for si in range(n)[::-1]:
        if ok(si):
            for i, c in enumerate(t): s[si+i] = c
            for i in range(n):
                if s[i] == "?": s[i] = "a"
            print("".join(s))
            return
    print(-1)

for _ in range(II()):
    solve()