import sys

N = int(input())
A = [0]*5
cnt = 0

for i in range(N):
    A[i]=input().split()
    if A[i].count("nyanpass") >= 2:
        print(-1)
        sys.exit()
    elif A[i].count("nyanpass") == 0:
        cnt += 1
        if cnt >= 2:
            print(-1)
            sys.exit()

if A[0].count("nyanpass") > 0:
    if A[0].index("nyanpass")+1 == N:
        print("1")
    else:
        print(A[0].index("nyanpass")+1)
else:
    print(A[1].index("nyanpass")+1)