class TimeMap:

    def __init__(self):
        self.hashmap = defaultdict(list)

    def set(self, key: str, value: str, timestamp: int) -> None:
        self.hashmap[key].append([value, timestamp])

    def get(self, key: str, timestamp: int) -> str:

        if key not in self.hashmap:
            return ""
        ans = ""
        store = self.hashmap[key]
        low, high = 0, len(store) - 1

        while low <= high:
            mid = (low + high)//2
            if store[mid][1] <= timestamp:
                ans = store[mid][0]
                low = mid + 1
            else:
                high = mid - 1

        return ans


# Your TimeMap object will be instantiated and called as such:
# obj = TimeMap()
# obj.set(key,value,timestamp)
# param_2 = obj.get(key,timestamp)