Multiples of seven P91736

For every natural $n$, let $X(n)$ be the smallest natural $m$ such that $m$ ends with $n$ and $m$ is a multiple of 7. For instance, $X(1) = 21$, $X(2) = 42$, $X(3) = 63$, …, $X(7) = 7$, $X(8) = 28$, $X(9) = 49$, $X(10) = 210$, $X(11) = 511$, … Let $S$ be the infinite concatenation of $X(i)$ for every $i \ge 1$, that is, $S = 21426314355672849210511...$. Which is the $i$-th digit of $S$?

Input

Input consists of several cases, each with a natural $i$ between 1 and $10^{15}$.

Output

For every $i$, print the $i$-th digit of $S$ (starting at one).