又是一道水（zuo si)题~~~

B - Making Sequences is Fun

Time Limit:2000MS     Memory Limit:262144KB     64bit IO Format:%I64d & %I64u

Submit Status

Description

We'll define S(n) for positive integer n as follows: the number of the n's digits in the decimal base. For example, S(893) = 3,S(114514) = 6.

You want to make a consecutive integer sequence starting from number m (m, m + 1, ...). But you need to pay S(n)·k to add the numbern to the sequence.

You can spend a cost up to w, and you want to make the sequence as long as possible. Write a program that tells sequence's maximum length.

Input

The first line contains three integers w (1 ≤ w ≤ 10¹⁶), m (1 ≤ m ≤ 10¹⁶), k (1 ≤ k ≤ 10⁹).

Please, do not write the %lld specifier to read or write 64-bit integers in C++. It is preferred to use the cin, cout streams or the %I64dspecifier.

Output

The first line should contain a single integer — the answer to the problem.

Sample Input

Input

9 1 1

Output

9

Input

77 7 7

Output

7

Input

114 5 14

Output

6

Input

1 1 2

Output

0

代码如下：

#include <cstdio>#include <iostream>#include <cmath>typedef unsigned long long ll;using namespace std;int main(){    int i = 0;    ll n = 1 , ans = 0, p = 0;    ll w, m, k;    cin >> w >> m >> k;    while(n <= m){        n *= 10;        i++;    }    p += i*(n-m)*k;    while(p < w){        ans += n-m;        m = n;        n *= 10;        i++;        p += i*(n-m)*k;    }    p -= i*(n-m)*k;    ans += (w-p)/(i*k);    cout << ans;}

//就为了unsigned long long 折腾了半天我容易吗我