Pop Sequence

def solve(m, sequence):
    m = int(m)
    sequence = list(map(int, sequence.split(',')))
    stack = []
    current = 1
    for num in sequence:
        while current <= num and len(stack) < m:
            stack.append(current)
            current += 1
        if not stack or stack[-1] != num:
            print('NO')
            return
        stack.pop()
    print('YES')