CodeForces 373B Making Sequences is Fun

Making Sequences is Fun

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

Submit Status Practice CodeForces 373B

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

 #include <stdio.h>
 #include <string.h>
 long long SS(long long a)
 {
     long long x=;
     while(a>)
     {
         a=a/;
         x++;
         //printf("%I64d\n",a);
     }
     return x;
 }

 long long num(long long x)
 {
     long long i,y=;
     for(i=;i<=x;i++)
         y=y*;
     return y;
 }
 int main()
 {
     long long w,m,k;
     int i,j;
     while(scanf("%I64d %I64d %I64d",&w,&m,&k)!=EOF)
     {
         long long n=,nu,ww,mm;
         long long oo=SS(m);
         nu=num(oo);
         ww=w/k;
         while(ww>)
         {
             mm=ww/oo;
             n=n+mm;
             if(n>=nu-m)
             {
                 mm=mm-(n-nu+m);
                 n=nu-m;
                 ww=ww-oo*mm;
                 oo++;
                 nu=num(oo);
             }
             else
             {
                 ww=ww-oo*mm;
             }
             if(mm==)
                 break;
             //printf("%I64d %I64d %I64d",ww,);
         }
         printf("%I64d\n",n);
     }
     return ;
 }