#include <bits/stdc++.h>
using namespace std;
const int N = 1e5;
const long long mod = 1e9 + 7;
char s[N + 10];
long long fac[N + 10], inv[N + 10], fp[N + 10], sum[N + 10];
inline long long power(long long a, long long b) {
  long long res = 1;
  while (b) {
    if (b & 1) res = res * a % mod;
    b >>= 1;
    a = a * a % mod;
  }
  return res;
}
inline long long C(int n, int m) {
  if (n < m) return 0;
  return fac[n] * inv[m] % mod * inv[n - m] % mod;
}
int main() {
  fac[0] = fp[0] = 1;
  for (int i = 1; i <= N; i++)
    fac[i] = fac[i - 1] * i % mod, fp[i] = fp[i - 1] * 10 % mod;
  inv[N] = power(fac[N], mod - 2);
  for (int i = N - 1; i >= 0; i--) inv[i] = inv[i + 1] * (i + 1) % mod;
  int n, k;
  long long ans = 0;
  scanf("%d%d", &n, &k);
  scanf("%s", s + 1);
  for (int i = 0; i < n; i++)
    sum[i] = (sum[i - 1] + fp[i] * C(n - 2 - i, k - 1) % mod) % mod;
  for (int i = 1; i <= n; i++)
    ans = (ans + (s[i] - '0') *
                     (sum[n - i - 1] + fp[n - i] * C(i - 1, k) % mod) % mod) %
          mod;
  printf("%lld\n", ans);
  return 0;
}
