class MemoryPool:
    def __init__(self, total_size=100):
        self.total_size = total_size
        self.memory = [None] * total_size  # 用列表模拟内存池
        self.allocated = {}  # 记录已分配的内存块 {起始地址: 大小}

    def request(self, size):
        if size <= 0 or size> self.total_size:
            return "error"
        
        # 寻找连续空闲内存
        start = 0
        while start < self.total_size:
            if self.memory[start] is None:
                end = start
                while end < self.total_size and self.memory[end] is None:
                    if end - start + 1 == size:
                        # 分配内存
                        for i in range(start, end + 1):
                            self.memory[i] = "allocated"
                        self.allocated[start] = size
                        return start
                    end += 1
                start = end + 1
            else:
                start += 1
        return "error"

    def release(self, address):
        if address not in self.allocated:
            return "error"
        
        # 释放内存
        size = self.allocated[address]
        for i in range(address, address + size):
            self.memory[i] = None
        del self.allocated[address]
        return None

# 处理输入
def process_commands(commands):
    memory_pool = MemoryPool()
    for cmd in commands:
        if cmd.startswith("REQUEST="):
            size = int(cmd.split("=")[1])
            result = memory_pool.request(size)
            if result is not None:
                print(result)
        elif cmd.startswith("RELEASE="):
            address = int(cmd.split("=")[1])
            result = memory_pool.release(address)
            if result == "error":
                print("error")
        else:
            print("error")

# 输入处理
N = int(input("请输入操作命令的个数: "))
commands = [input(f"请输入第 {i + 1} 个操作命令: ") for i in range(N)]

# 执行命令
process_commands(commands)