#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int , int> pii;
typedef pair<ll , ll> pll;

int a , b , n;
vector<int> v;
int dp[15][110][2];
int dfs(int pos , int sum , bool lm)
{
    if(dp[pos][sum][lm] != -1) return dp[pos][sum][lm];
    if(pos == v.size())
    {
        return (sum % n == 0) ? 1 : 0;
    }
    int ans = 0 , up = lm ? v[pos]: 9;
    for(int i = 0 ; i <= up ; i ++)
    {
        ans += dfs(pos + 1 , sum + i , lm ? (i == up) : false);
    }
    dp[pos][sum][lm] = ans;
    return ans;
}

int cnt(int num)
{
    if(num == 0) return 1;
    memset(dp , -1 ,sizeof(dp));
    v.clear();
    while(num)
    {
        v.push_back(num % 10);
        num /= 10;
    }
    reverse(v.begin() , v.end());
    return dfs(0 , 0 , true);
}
void solve()
{
    while(cin >> a >> b >> n)
        cout << cnt(b) - cnt(a - 1) <<'\n';
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    solve();
    return 0;
}