input() d=0 a=list(map(int,input().split())) b=int(input()) if b not in a: print(-1) else: c= 0 d =0 f = 0 for i in range(len(a)): if a[i]==b and f == 0: c=i+1 d = c f = 1 elif a[i]==b: d = i+1 print("{} {}".format(c,d))