1246 : Phone numbers

时间限制:1 Sec 内存限制:128 MiB
提交:81 答案正确:64

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题目描述

Phone number in Berland is a sequence of n digits. Often, to make it easier to memorize the number, it is divided into groups of three digits. For example, the phone number 119733 is easier to remember as 119-733. Your task is to find for a given phone number divisions into groups of three digits.

输入

N cases,Each case the first line contains integer n (3 ≤ n ≤ 100) (n is a multiple of 3
)— amount of digits in the phone number. The second line contains n digits — the phone number to divide into groups.

输出

Output divisions of the given phone number into groups of three digits. Separate groups by single character -.

样例输入

复制
2
6
549871
3
117

样例输出

复制
549-871
117

提示


			

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