n,m=map(int,input().split())
a=map(int,input().split())
array=[]
for i in range(1,n+1):
    array.append(i)

for _ in range(m):
    for i in a:
        ans=array[i-1]
        array.pop(i-1)
        array.insert(0,ans)
print(array[0])