10799: ABC146 - C - Buy an Integer
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Description
Takahashi has come to an integer shop to buy an integer.
The shop sells the integers from $1$ through $10^9$. The integer $N$ is sold for $A \times N + B \times d(N)$ yen (the currency of Japan), where $d(N)$ is the number of digits in the decimal notation of $N$.
Find the largest integer that Takahashi can buy when he has $X$ yen. If no integer can be bought, print $0$.
The shop sells the integers from $1$ through $10^9$. The integer $N$ is sold for $A \times N + B \times d(N)$ yen (the currency of Japan), where $d(N)$ is the number of digits in the decimal notation of $N$.
Find the largest integer that Takahashi can buy when he has $X$ yen. If no integer can be bought, print $0$.
Input
Input is given from Standard Input in the following format:
```
$A$ $B$ $X$
```
```
$A$ $B$ $X$
```
Output
Print the greatest integer that Takahashi can buy. If no integer can be bought, print $0$.
Constraints
- All values in input are integers.
- $1 \leq A \leq 10^9$
- $1 \leq B \leq 10^9$
- $1 \leq X \leq 10^{18}$
- $1 \leq A \leq 10^9$
- $1 \leq B \leq 10^9$
- $1 \leq X \leq 10^{18}$
Sample 1 Input
10 7 100
Sample 1 Output
9
The integer $9$ is sold for $10 \times 9 + 7 \times 1 = 97$ yen, and this is the greatest integer that can be bought. Some of the other integers are sold for the following prices:
- $10: 10 \times 10 + 7 \times 2 = 114$ yen
- $100: 10 \times 100 + 7 \times 3 = 1021$ yen
- $12345: 10 \times 12345 + 7 \times 5 = 123485$ yen
Sample 2 Input
2 1 100000000000
Sample 2 Output
1000000000
He can buy the largest integer that is sold. Note that input may not fit into a $32$-bit integer type.
Sample 3 Input
1000000000 1000000000 100
Sample 3 Output
0
1234 56789 314159265
254309