#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
char str[100005];
int sum[100005], fac[100005], fac_[100005];
int Pow(int x) {
  int k = mod - 2, res = 1;
  while (k) {
    if (k & 1) res = 1ll * res * x % mod;
    x = 1ll * x * x % mod;
    k >>= 1;
  }
  return res;
}
void Init() {
  fac[0] = 1;
  for (int i = 1; i <= 1e5; i++) fac[i] = 1ll * fac[i - 1] * i % mod;
  for (int i = 0; i <= 1e5; i++) fac_[i] = Pow(fac[i]);
}
int C(int n, int m) { return 1ll * fac[n] * fac_[m] % mod * fac_[n - m] % mod; }
int main() {
  Init();
  int n, K;
  cin >> n >> K;
  scanf("%s", str + 1);
  for (int i = 1; i <= n; i++) sum[i] = sum[i - 1] + (str[i] ^ 48);
  int mx = n - K, p10 = 1, ans = 0;
  for (int i = 1; i <= mx; i++, p10 = 10ll * p10 % mod)
    ans = (ans + (1ll * sum[n - i] * C(n - i - 1, K - 1) % mod +
                  1ll * (str[n - i + 1] ^ 48) * C(n - i, K) % mod) *
                     p10 % mod) %
          mod;
  cout << ans << endl;
  return 0;
}
