#include <bits/stdc++.h>
using namespace std;
long long n, k, ans;
long long d[100010], sd[100010], frac[100010], inv[100010], pw[100010];
string s;
long long read() {
  long long r = 0, f = 1;
  char c = getchar();
  while (c < '0' || c > '9') {
    if (c == '-') f = -1;
    c = getchar();
  }
  while (c <= '9' && c >= '0') r = (r << 1) + (r << 3) + c - '0', c = getchar();
  return r * f;
}
void put(long long x) {
  if (x < 0) {
    putchar('-');
    x = ~x + 1;
  }
  if (x > 9) put(x / 10);
  putchar(x % 10 + '0');
}
long long poww(long long x, long long y) {
  long long s = 1;
  while (y) {
    if (y & 1) s = s * x % 1000000007;
    x = x * x % 1000000007, y >>= 1;
  }
  return s;
}
long long get_c(long long nn, long long kk) {
  return frac[nn] * inv[kk] % 1000000007 * inv[nn - kk] % 1000000007;
}
signed main() {
  n = read(), k = read();
  cin >> s;
  for (long long i = 0; i < n; i++) d[i + 1] = s[i] - '0';
  for (long long i = 1; i <= n; i++) sd[i] = (sd[i - 1] + d[i]) % 1000000007;
  pw[0] = 1;
  for (long long i = 1; i <= n; i++) pw[i] = pw[i - 1] * 10 % 1000000007;
  frac[0] = 1;
  for (long long i = 1; i <= n; i++) frac[i] = frac[i - 1] * i % 1000000007;
  inv[n] = poww(frac[n], 1000000007 - 2);
  for (long long i = n - 1; i >= 0; i--)
    inv[i] = inv[i + 1] * (i + 1) % 1000000007;
  for (long long i = 0; i < n - k; i++)
    ans = (ans + pw[i] * get_c(n - i - 2, k - 1) % 1000000007 * sd[n - i - 1] %
                     1000000007) %
          1000000007;
  for (long long i = k; i <= n; i++)
    ans = (ans + d[i] * pw[n - i] % 1000000007 * get_c(i - 1, k) % 1000000007) %
          1000000007;
  put(ans);
  puts("");
  return 0;
}
