#include <bits/stdc++.h>
using namespace std;
int N, M, Ans, A[100005], B[100005];
char s[100005];
int Pow(int a, int b) {
  int ret = 1;
  for (; b; b >>= 1, a = 1ll * a * a % 1000000007)
    if (b & 1) ret = 1ll * ret * a % 1000000007;
  return ret;
}
int C(int a, int b) {
  if (b > a || a < 0 || b < 0) return 0;
  return 1ll * A[a] * B[b] % 1000000007 * B[a - b] % 1000000007;
}
int main() {
  scanf("%d%d%s", &N, &M, s + 1);
  A[0] = 1;
  for (int i = 1; i <= N; i++) A[i] = 1ll * A[i - 1] * i % 1000000007;
  B[N] = Pow(A[N], 1000000007 - 2);
  for (int i = N; i; i--) B[i - 1] = 1ll * B[i] * i % 1000000007;
  for (int i = N, tmp = 1, sum = 0; i; i--) {
    (Ans += (1ll * sum * (s[i] - '0') +
             1ll * tmp * (s[i] - '0') % 1000000007 * C(i - 1, M)) %
            1000000007) %= 1000000007;
    (sum += 1ll * tmp * C(i - 2, M - 1) % 1000000007) %= 1000000007;
    tmp = 1ll * tmp * 10 % 1000000007;
  }
  printf("%d\n", Ans);
}
