#include <bits/stdc++.h>
using namespace std;
const int maxn = 999;
const int mod = 998244353;
long long dp1[maxn][2000];
long long cnt[maxn][2222];
long long val[maxn];
struct node {
  long long cnt, sum;
  node() {}
  node(long long c, long long s) {
    cnt = c;
    sum = s;
  }
};
long long f[maxn];
void init() {
  f[0] = 1;
  for (long long i = 1; i < maxn; i++) {
    f[i] = (f[i - 1] * 10) % mod;
  }
}
long long kk;
node dfs(long long pos, long long sta, long long limit) {
  if (pos == -1) {
    long long cnt1 = 0;
    while (sta) {
      if (sta & 1) cnt1++;
      sta /= 2;
    }
    return node(cnt1 <= kk, 0);
  }
  if (cnt[pos][sta] != -1 && !limit) return node(cnt[pos][sta], dp1[pos][sta]);
  long long up = limit ? val[pos] : 9;
  long long nowcnt = 0;
  long long nowsum = 0;
  for (long long i = 0; i <= up; i++) {
    long long newsta = sta;
    if (i != 0 || newsta != 0) newsta |= (1 << i);
    node o = dfs(pos - 1, newsta, limit && i == up);
    nowcnt += o.cnt;
    nowsum += o.sum + ((f[pos] * i) % mod * o.cnt) % mod;
    nowsum %= mod;
    nowcnt %= mod;
  }
  if (!limit) {
    cnt[pos][sta] = nowcnt;
    dp1[pos][sta] = nowsum;
  }
  return node(nowcnt, nowsum);
}
void solve() {
  memset(cnt, -1, sizeof(cnt));
  long long l, r;
  scanf("%lld %lld %lld", &l, &r, &kk);
  l--;
  init();
  long long arr = -1;
  while (r) {
    val[++arr] = r % 10;
    r /= 10;
  }
  if (arr == -1) val[++arr] = 0;
  long long ans = 0;
  node aa = dfs(arr, 0, 1);
  ans += aa.sum;
  arr = -1;
  while (l) {
    val[++arr] = l % 10;
    l /= 10;
  }
  if (arr == -1) val[++arr] = 0;
  aa = dfs(arr, 0, 1);
  ans -= aa.sum;
  ans %= mod;
  ans += mod * 2;
  ans %= mod;
  printf("%lld\n", ans);
}
signed main() { solve(); }
