func_code_string: #include <bits/stdc++.h>   using namespace std;   char gc() {     static char buf[100000], *p1 = buf, *p2 = buf;     return p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 100000, stdin), p1 == p2)                ? EOF                : *p1++;   }   long long read() {     char ch = getchar();     long long x = 0;     int op = 1;     for (; !isdigit(ch); ch = getchar())       if (ch ==  - ) op = -1;     for (; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch -  0 ;     return x * op;   }   int n, k, a[55], ans;   char s[55];   int main() {     n = read(), k = read();     scanf( %s , s + 1);     for (int i = (1); i <= (n); i++) a[i] = s[i] -  a  + 1;     sort(&a[1], &a[n + 1]);     ans = 1000000001;     for (int i = (1); i <= (n); i++) {       int p = i, q, tmp = 0;       bool flag = 1;       for (int j = (1); j <= (k); j++) {         if (p > n) {           flag = 0;           break;         }         tmp += a[p];         q = p, p++;         while (p <= n && abs(a[p] - a[q]) <= 1) p++;       }       if (flag) ans = min(ans, tmp);     }     if (ans == 1000000001)       puts( -1 );     else       printf( %d n , ans);     return 0;   }   