#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 5, mod = 998244353;
int a[20];
int k;
long long p[25];
pair<long long, long long> dp[20][1 << 15];
pair<long long, long long> dfs(int pos, int statu, bool zero, bool limit) {
  if (!pos) return make_pair(__builtin_popcount(statu) <= k, 0);
  if (!limit && !zero && dp[pos][statu].first != -1) return dp[pos][statu];
  int up = limit ? a[pos] : 9;
  pair<long long, long long> ans = make_pair(0, 0);
  for (int i = 0; i <= up; i++) {
    pair<long long, long long> res;
    if (zero && i == 0)
      res = dfs(pos - 1, statu, zero, limit && i == up);
    else
      res = dfs(pos - 1, statu | (1 << i), zero && i == 0, limit && i == up);
    ans.first = (ans.first + res.first) % mod;
    ans.second =
        (ans.second + res.second + i * res.first % mod * p[pos - 1] % mod) %
        mod;
  }
  if (!limit && !zero) dp[pos][statu] = ans;
  return ans;
}
long long cal(long long x) {
  int tot = 0;
  while (x) {
    a[++tot] = x % 10;
    x = x / 10;
  }
  memset(dp, -1, sizeof(dp));
  return dfs(tot, 0, 1, 1).second;
}
void solve() {
  long long l, r;
  p[0] = 1LL;
  for (int i = 1; i <= 20; i++) p[i] = (p[i - 1] * 10LL) % mod;
  scanf("%lld %lld %d", &l, &r, &k);
  long long ans = (cal(r) - cal(l - 1) + mod) % mod;
  printf("%lld\n", ans);
}
int main() {
  solve();
  return 0;
}
