#include <bits/stdc++.h>
using namespace std;
int n, k;
long long fat[100100], ifat[100100], powt[100100], acum[10][100100];
string s;
long long fpow(long long base, long long exp) {
  if (exp < 1) return 1;
  long long ret = fpow(base, exp / 2);
  ret *= ret;
  ret %= 1000000007;
  if (exp & 1) ret *= base;
  return ret % 1000000007;
}
long long comb(long long a, long long b) {
  if (a < b || b < 0) return 0;
  return (((fat[a] * ifat[b]) % 1000000007) * ifat[a - b]) % 1000000007;
}
int main() {
  scanf("%d %d", &n, &k);
  cin >> s;
  for (int i = 0; i < n - 1; i++) acum[s[i] - '0'][n - i - 2]++;
  for (int i = 0; i < 10; i++)
    for (int j = n; j >= 0; j--) acum[i][j] += acum[i][j + 1];
  fat[0] = 1;
  ifat[0] = 1;
  powt[0] = 1;
  for (int i = 1; i < 100100; i++) {
    fat[i] = fat[i - 1] * i;
    fat[i] %= 1000000007;
    ifat[i] = fpow(fat[i], 1000000007 - 2);
    powt[i] = powt[i - 1] * 10;
    powt[i] %= 1000000007;
  }
  long long ans = 0;
  for (int i = 0; i < 10; i++)
    for (int j = 0; j < n; j++) {
      ans += (((((acum[i][j] * i) % 1000000007) * powt[j]) % 1000000007) *
              comb(n - j - 2, k - 1)) %
             1000000007;
      ans %= 1000000007;
    }
  for (int i = 0; i < n; i++) {
    ans += ((((s[i] - '0') * powt[n - i - 1]) % 1000000007) * comb(i, k)) %
           1000000007;
    ans %= 1000000007;
  }
  printf("%lld\n", ans);
  return 0;
}
