class Node:
    def __init__(self, x):
        self.x = x
        self.prev = None
        self.next = None


n, m = map(int, input().split())
a = list(map(int, input().split()))
root = Node(1)
current = root
for i in range(2, n + 1):
    node = Node(i)
    current.next = node
    node.prev = current
    current = node

for x in a:
    current = root
    cnt = 1
    while cnt < x:
        current = current.next
        cnt += 1
    if current.prev:
        if current.next:
            current.prev.next = current.next
            current.next.prev = current.prev
        else:
            current.prev.next = None
        current.prev = None
        current.next = root
        root.prev = current
        root = current

print(root.x)