Shifted Multiples
For a positive integer , let be the integer obtained by shifting the leftmost digit of the decimal representation of to the rightmost position.
For example, and .
For a positive rational number , we define as the smallest positive integer such that .
If no such integer exists, then is defined as zero.
For example, , and .
Let be the sum of where ranges over all ordered pairs of coprime positive integers not exceeding .
For example, .
Find . Give your answer modulo .
数字轮转倍数
对于正整数,记为将的十进制表示下最左侧数字移到最右侧所得到的数。
例如,,。
对于正有理数,定义为满足的最小正整数。
若不存在这样的正整数,则取零。
例如,,,。
对于所有不超过的互质正整数对,记为所有之和。
例如,。
求,并将你的答案对取余。
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