#include <bits/stdc++.h>
using namespace std;
const long long p = 1e9 + 7, N = 2e5 + 100;
long long n, k, res, fact[N], sum[N];
string s;
long long power(long long a, long long b) {
  long long ans = 1;
  while (b > 0) {
    if (b & 1) ans = (ans * a) % p;
    b /= 2;
    a = (a * a) % p;
  }
  return ans;
}
long long ncr(long long n, long long r) {
  if (r > n) return 0;
  long long ans = fact[n];
  ans *= power(fact[n - r], p - 2);
  ans %= p;
  ans *= power(fact[r], p - 2);
  ans %= p;
  return ans;
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> k >> s;
  fact[0] = 1;
  for (long long i = 0; i < n; i++) {
    fact[i + 1] = (fact[i] * (i + 1)) % p;
    sum[i + 1] = (sum[i] + s[i] - '0') % p;
  }
  for (long long i = 0; i < n; i++) {
    res += (ncr(n - i - 2, k - 1) * power(10, i) % p * sum[n - i - 1]) % p;
    res %= p;
    res += (ncr(n - i - 1, k) * power(10, i) % p * (s[n - i - 1] - '0')) % p;
    res %= p;
  }
  cout << res << endl;
  return 0;
}
