N = int(input())
nyan = [1]*N
for i in range(N):
    hello = list(input().split())
    nyan = [ny and (h == 'nyanpass' or h == '-') for ny, h in zip(nyan, hello)]
if sum(nyan) == 1:
    print(nyan.index(1) + 1)
else:
    print(-1)