#include <bits/stdc++.h>
using namespace std;
int SIZE = 100010;
long long inv[100100], fac[100100], facinv[100100];
long long p[100100];
long long nCr(int n, int r) {
  if (n < r) return 0ll;
  if (n < 0 || r < 0) return 0ll;
  return ((fac[n] * facinv[r] % 1000000007) * facinv[n - r]) % 1000000007;
}
int main() {
  int n, k;
  string s;
  cin >> n >> k;
  cin >> s;
  reverse((s).begin(), (s).end());
  fac[0] = 1;
  for (int i = 1; i <= SIZE; i++) fac[i] = (fac[i - 1] * i) % 1000000007;
  inv[1] = 1;
  for (int i = 2; i <= SIZE; i++)
    inv[i] =
        ((-(1000000007 / i) * inv[1000000007 % i]) % 1000000007 + 1000000007) %
        1000000007;
  facinv[0] = 1;
  for (int i = 1; i <= SIZE; i++)
    facinv[i] = (facinv[i - 1] * inv[i]) % 1000000007;
  p[0] = 1;
  for (int i = 1; i <= SIZE; i++) p[i] = (p[i - 1] * 10) % 1000000007;
  long long ans = 0ll;
  for (int i = 0; i < n; i++) {
    ans += (((nCr(n - i - 1, k) * p[i]) % 1000000007) *
            ((long long)(s[i] - '0'))) %
           1000000007;
    ans %= 1000000007;
  }
  long long sum = 0ll;
  for (int i = n - 1; i >= 1; i--) {
    sum = (sum + (long long)(s[i] - '0')) % 1000000007;
    ans += ((nCr(n - i - 1, k - 1) * sum) % 1000000007) * p[i - 1] % 1000000007;
    ans %= 1000000007;
  }
  cout << ans << endl;
  return 0;
}
