#include <bits/stdc++.h>
using namespace std;
long long fat[110000];
long long exp(long long a, long long b) {
  if (b == 0) return 1;
  long long ret = exp(a, b / 2);
  ret *= ret;
  ret %= 1000000007;
  if (b % 2 == 1) ret = (ret * a) % 1000000007;
  return ret;
}
long long inv(long long a) { return exp(a, 1000000007 - 2); }
long long B(long long a, long long b) {
  if (b > a) return 0;
  if (b < 0) return 0;
  long long ret = fat[a];
  ret *= inv(fat[b]);
  ret %= 1000000007;
  ret *= inv(fat[a - b]);
  ret %= 1000000007;
  return ret;
}
int n, k;
string s;
int main() {
  fat[0] = 1;
  for (long long i = 1; i < 110000; i++) {
    fat[i] = (fat[i - 1] * i) % 1000000007;
  }
  cin >> n >> k;
  cin >> s;
  int d = 2;
  long long mul = 1;
  long long C = 0;
  long long ans = 0;
  ans = (long long)(s[n - 1] - '0') * B(n - 1, k);
  for (int i = n - 2; i >= 0; i--) {
    C += (mul * B(i, k - 1)) % 1000000007;
    C %= 1000000007;
    ans += (long long)(s[i] - '0') * (C);
    ans %= 1000000007;
    mul *= 10LL;
    mul %= 1000000007;
    long long aux = ((long long)(s[i] - '0') * B(i, k));
    aux %= 1000000007;
    aux *= mul;
    aux %= 1000000007;
    ans += aux;
    ans %= 1000000007;
  }
  cout << ans << endl;
  return 0;
}
