import std;

int calc(int k, int[] a) {
    a.sort!"a > b";
    auto ans = a[0] + a[1..$].until!"a < 0".take(k-1).sum;
    return ans;
}

void main() {
    int n, k; scan(n, k);
    auto a = readints;
    writeln(calc(k, a));
}

void scan(T...)(ref T a) {
    string[] ss = readln.split;
    foreach (i, t; T) a[i] = ss[i].to!t;
}
T read(T=string)() { return readln.chomp.to!T; }
T[] reads(T)() { return readln.split.to!(T[]); }
alias readints = reads!int;