#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
char s[100007];
int sum[100007];
long long fac[100007], inv[100007];
inline long long qpow(long long a, long long b) {
  long long c = 1;
  while (b) {
    if (b & 1) c = c * a % MOD;
    a = a * a % MOD;
    b >>= 1;
  }
  return c;
}
inline long long comb(long long n, long long m) {
  if (n < m) return 0;
  return fac[n] * inv[m] % MOD * inv[n - m] % MOD;
}
int main() {
  fac[0] = 1;
  for (int i = int(1); i <= int(100000); ++i) fac[i] = fac[i - 1] * i % MOD;
  for (int i = int(0); i <= int(100000); ++i) inv[i] = qpow(fac[i], MOD - 2);
  int n, k;
  scanf("%d%d", &n, &k);
  scanf("%s", s + 1);
  for (int i = int(1); i <= int(n); ++i) sum[i] = sum[i - 1] + (s[i] - '0');
  long long ans = 0;
  for (int j = int(0); j <= int(n - 2); ++j) {
    ans += qpow(10, j) * comb(n - 2 - j, k - 1) % MOD * sum[n - j - 1] % MOD;
    ans %= MOD;
  }
  for (int i = int(1); i <= int(n); ++i) {
    ans += (s[i] - '0') * qpow(10, n - i) % MOD * comb(i - 1, k) % MOD;
    ans %= MOD;
  }
  cout << ans << endl;
}
