#include <iostream>

#include <cstdio>

#include <algorithm>

#include <cstdlib>

#include <cstring>

#define in(a) a=read()

#define REP(i,k,n)  for(int i=k;i<=n;i++)

using namespace std;

inline int read(){

    int x=,f=;

    char ch=getchar();

    for(;!isdigit(ch);ch=getchar())

        if(ch=='-')

            f=-;

    for(;isdigit(ch);ch=getchar())

        x=x*+ch-'';

    return x*f;

}

int a,b,n,digit[],dp[][],ind;

inline int dfs(int pos,int state,bool flag){

    if(!pos)  return state==;

    if(!flag && dp[pos][state]!=-)  return dp[pos][state];

    int up,ans=;

    if(flag)  up=digit[pos];

    else  up=;

    REP(i,,up)

        ans+=dfs(pos-,(state+i)%n,flag && i==digit[pos]);

    if(!flag)  dp[pos][state]=ans;

    return ans;

}

inline int solve(int x){

    ind=;

    while(x){

        digit[++ind]=x%;

        x/=;

    }

    digit[ind+]=-;

    return dfs(ind,,);

}

int main(){

    while(scanf("%d%d%d",&a,&b,&n)!=EOF){

        memset(dp,-,sizeof(dp));

        printf("%d\n",solve(b)-solve(a-));

    }

}