#include <bits/stdc++.h>
using namespace std;
template <typename T, typename U>
inline void smin(T &a, U b) {
  if (a > b) a = b;
}
template <typename T, typename U>
inline void smax(T &a, U b) {
  if (a < b) a = b;
}
template <class T>
inline void gn(T &first) {
  char c, sg = 0;
  while (c = getchar(), (c > '9' || c < '0') && c != '-')
    ;
  for ((c == '-' ? sg = 1, c = getchar() : 0), first = 0; c >= '0' && c <= '9';
       c = getchar())
    first = (first << 1) + (first << 3) + c - '0';
  if (sg) first = -first;
}
template <class T, class T1>
inline void gn(T &first, T1 &second) {
  gn(first);
  gn(second);
}
template <class T, class T1, class T2>
inline void gn(T &first, T1 &second, T2 &z) {
  gn(first);
  gn(second);
  gn(z);
}
template <class T>
inline void print(T first) {
  if (first < 0) {
    putchar('-');
    return print(-first);
  }
  if (first < 10) {
    putchar('0' + first);
    return;
  }
  print(first / 10);
  putchar(first % 10 + '0');
}
template <class T>
inline void printsp(T first) {
  print(first);
  putchar(' ');
}
template <class T>
inline void println(T first) {
  print(first);
  putchar('\n');
}
template <class T, class U>
inline void print(T first, U second) {
  printsp(first);
  println(second);
}
template <class T, class U, class V>
inline void print(T first, U second, V z) {
  printsp(first);
  printsp(second);
  println(z);
}
int power(int a, int b, int m, int ans = 1) {
  for (; b; b >>= 1, a = 1LL * a * a % m)
    if (b & 1) ans = 1LL * ans * a % m;
  return ans;
}
const int E = 111111;
int dp[E], nam[E], ans, i, n, k;
int ch[E], re[E], po[E];
char s[E];
int comb(int n, int m) {
  if (m < 0 || m > n) return 0;
  return (long long)ch[n] * re[m] % 1000000007 * re[n - m] % 1000000007;
}
void pre() {
  for (i = ch[0] = 1; i < E; i++) ch[i] = (long long)ch[i - 1] * i % 1000000007;
  for (i = E - 1, re[E - 1] = power(ch[E - 1], 1000000007 - 2, 1000000007);
       i > 0; i--)
    re[i - 1] = (long long)re[i] * i % 1000000007;
  for (i = po[0] = 1; i < E; i++)
    po[i] = (long long)po[i - 1] * 10 % 1000000007;
  for (i = 1; i <= n; i++)
    nam[i] = (nam[i - 1] + (long long)po[i - 1] * comb(n - i - 2, k - 2)) %
             1000000007;
  return;
}
void solve_E() {
  gn(n, k);
  pre();
  scanf("%s", s + 1);
  for (i = n - 1, dp[n] = comb(n - 1, k); i > 0; i--) {
    dp[i] = ((long long)dp[i + 1] - nam[n - i - 1] -
             (long long)po[n - i - 1] * comb(i - 1, k - 1)) %
            1000000007;
    if (dp[i] < 0) dp[i] += 1000000007;
    dp[i] = (long long)dp[i] * 10 % 1000000007;
    dp[i] += comb(n - 2, k - 1);
    if (dp[i] >= 1000000007) dp[i] -= 1000000007;
  }
  for (i = 1; i <= n; i++) {
    ans += (long long)dp[i] * (s[i] - '0') % 1000000007;
    if (ans >= 1000000007) ans -= 1000000007;
  }
  println(ans);
  exit(0);
}
int main() {
  solve_E();
  return 0;
}
