#AT1939. G - 222
G - 222
G - 222
Score : $600$ points
Problem Statement
We have a sequence $2,22,222,2222,\ldots$, where the $i$-th term is an $i$-digit integer whose digits are all $2$.
Where does a multiple of $K$ appear in this sequence for the first time? If the first multiple of $K$ is the $x$-th term of the sequence, print $x$; if there is no multiple of $K$, print -1
.
Given $T$ cases, solve each of them.
Constraints
- $1 \leq T \leq 200$
- $1 \leq K \leq 10^8$
- All values in input are integers.
Input
Input is given from Standard Input in the following format:
Each case is in the following format:
``` $K$ ```Output
Print $T$ lines. The $i$-th line should contain the answer for $\text{case}_i$.
4
1
7
10
999983
1
6
-1
999982
We have four cases.
- $2$ is a multiple of $1$.
- None of $2,22,222,2222,22222$ is a multiple of $7$, but $222222$ is.
- None of $2,22,\ldots$ is a multiple of $10$.
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