#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 10;
const int mod = 1e9 + 7;
int n, k, ans, fav[N], fac[N], S[N], pw[N], SS[N];
char s[N];
int C(int n, int m) {
  return n < m || m < 0 || n < 0
             ? 0
             : 1ll * fac[n] * fav[m] % mod * fav[n - m] % mod;
}
int qpow(int a, int b) {
  int ans = 1;
  for (; b >= 1; b >>= 1, a = 1ll * a * a % mod)
    if (b & 1) ans = 1ll * ans * a % mod;
  return ans;
}
void binom(int n) {
  fac[0] = 1;
  for (int i = 1; i <= n; i++) fac[i] = 1ll * fac[i - 1] * i % mod;
  fav[n] = qpow(fac[n], mod - 2);
  for (int i = n; i >= 1; i--) fav[i - 1] = 1ll * fav[i] * i % mod;
}
int main() {
  scanf("%d%d%s", &n, &k, s + 1);
  binom(n);
  pw[0] = 1;
  for (int i = 1; i <= n; ++i) pw[i] = 10ll * pw[i - 1] % mod;
  for (int i = 1; i <= n; ++i) S[i] = (10ll * S[i - 1] + (s[i] & 15)) % mod;
  for (int i = 1; i <= n; ++i) SS[i] = (SS[i - 1] + S[i]) % mod;
  if (k == 0) {
    printf("%d\n", S[n]);
    return 0;
  }
  for (int len = 1; len <= n - 2; ++len) {
    int cur = ((SS[n - 1] - SS[len] + mod) % mod -
               1ll * pw[len] * SS[n - len - 1] % mod + mod) %
              mod;
    (ans += 1ll * C(n - len - 2, k - 2) * cur % mod) %= mod;
  }
  for (int i = 1; i <= n; ++i) {
    (ans += 1ll * C(n - 1 - i, k - 1) * S[i] % mod) %= mod;
  }
  int ret = 0;
  for (int i = n; i >= 1; --i) {
    (ret += 1ll * (s[i] & 15) * pw[n - i] % mod) %= mod;
    (ans += 1ll * C(n - 1 - (n - i + 1), k - 1) * ret % mod) %= mod;
  }
  printf("%d\n", ans);
  return 0;
}
