Message Relay Communication

You are given a set of messages exchanged between employees and several queries. Each message is described by a sender, a recipient, and a timestamp. For each query, you must determine if there exists a chain of messages (a communication relay) which starts from the specified start employee and reaches the specified end employee, while respecting the time constraints. More formally, given a query with start time \(t_s\) and end time \(t_e\), a valid communication chain is a sequence of messages \((m_1, m_2, \ldots, m_k)\) such that:

• The sender of \(m_1\) is the start employee and the recipient of \(m_k\) is the end employee.
• Each message \(m_i\) has a timestamp \(t_i\) satisfying \(t_s \le t_i \le t_e\).
• The timestamps are non-decreasing, i.e. \(t_1 \le t_2 \le \cdots \le t_k\).

Output "YES" if such a chain exists for the query, and "NO" otherwise.

inputFormat

The input is read from standard input (stdin) and is structured as follows:

1. An integer \(N\) representing the number of messages.
2. \(N\) lines follow, each containing a message in the format: sender recipient timestamp. sender and recipient are strings (without spaces) and timestamp is an integer.
3. An integer \(Q\) representing the number of queries.
4. \(Q\) lines follow, each containing a query in the format: start end start_time end_time, where start and end are employee names (strings) and start_time and end_time are integers.

outputFormat

For each query, print either "YES" or "NO" (each on a separate line) to standard output (stdout) indicating whether a valid communication chain exists.

## sample

6
Alice Bob 1
Bob Charlie 2
Charlie Dave 4
Alice Eve 3
Eve Bob 5
Bob Alice 6
3
Alice Dave 1 4
Alice Charlie 1 5
Eve Charlie 2 6

YES
YES
NO

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