#include <bits/stdc++.h>
using namespace std;
const long long P = 1000000000 + 7;
long long ans;
char s[100003];
long long d[100003], sum[100003], fac[100003];
void init(int n) {
  d[0] = 1;
  for (int i = 1; i < n; i++) d[i] = (d[i - 1] * 10) % P;
  sum[0] = s[0] - '0';
  for (int i = 1; i < n; i++) sum[i] = sum[i - 1] + s[i] - '0';
  fac[0] = 1;
  for (int i = 1; i <= n; i++) fac[i] = (fac[i - 1] * i) % P;
}
long long inv(long long a, long long b) {
  if (b == 0) return 1;
  long long tmp = inv(a, b / 2);
  if (b % 2 == 0)
    return tmp * tmp % P;
  else
    return tmp * tmp % P * a % P;
}
long long comb(int a, int b) {
  if (a < b) return 0;
  return fac[a] * inv(fac[b] * fac[a - b] % P, P - 2) % P;
}
int main() {
  int n, k;
  scanf("%d%d", &n, &k);
  gets(s);
  gets(s);
  init(n);
  ans = 0;
  for (int l = 0; l <= n - 2; l++)
    ans = (ans + d[l] * comb(n - l - 2, k - 1) % P * sum[n - l - 2]) % P;
  for (int i = 0; i <= n - 1; i++)
    ans = (ans + (s[i] - '0') * d[n - i - 1] * comb(i, k)) % P;
  cout << ans << endl;
  return 0;
}
