n = int(input())
check = [1 for _ in range(n)]
for _ in range(n):
    a = list(input().split())
    for i, s in enumerate(a):
        if s == "-":
            continue
        elif s != "nyanpass":
            check[i] = 0
if sum(check) == 1:
    print(check.index(1) + 1)
else:
    print(-1)