#include <bits/stdc++.h>   using namespace std;   const int max_n = 200222, inf = 1000111222;   int n, m, a[max_n];   bool check(int cnt) {     long long sum = 0;     int last = 1;     for (int i = 0; i < n; ++i) {       if (i % cnt == 0) --last;       if (a[i] + last < 0) break;       sum += (a[i] + last);     }     return sum >= m;   }   int main() {     scanf( %d%d , &n, &m);     for (int i = 0; i < n; ++i) scanf( %d , &a[i]);     sort(a, a + n);     reverse(a, a + n);     int l = 0, r = n + 1;     while (r - l > 1) {       int mid = (l + r) / 2;       if (check(mid))         r = mid;       else         l = mid;     }     if (r > n)       puts( -1 );     else       printf( %d n , r);     return 0;   }   