func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int n, k;     cin >> n >> k;     bool count[26] = {0};     char c;     for (int i = 0; i < n; i++) {       cin >> c;       count[c -  a ] = true;     }     int e = -4;     int res = 0;     for (int i = 0; i < 26; i++) {       if ((!count[i]) || (i - e) < 2) continue;       res += i + 1;       e = i;       k--;       if (k == 0) break;     }     if (k > 0) {       cout <<  -1 n ;     } else       cout << res <<   n ;   }   