Chen_Yu_Wei @ 2024-08-15 19:16:13
n,m = map(int,input().split())
l1 = list(map(int,input().split()))
l2 = list(map(int,input().split()))
x = []
for i in l2:
s = len(l1)//2
x = [s]
while 1:
if i==l1[s]:
while i==l1[s]:
s -= 1
print(s+2,end=' ')
break
elif i<l1[s]:
s = s//2
else:
s = s+s//2
if s in x:
print(-1,end=' ')
break
x.append(s)