import std.stdio, std.string, std.conv
	,std.array,std.algorithm, std.range
	,std.math;

void main(){
	auto buf = readln().strip().split().map!(to!int)();
  immutable int N = buf[0];
  immutable int V = buf[1];

	auto C = readln().strip().split().map!(to!int)();

  int now = 0;
  long ans = 0;

  long[100] cos;
  double[100] costd;

  cos[0] = C[0];

  foreach(immutable int i; 1 .. N)
    cos[i] = cos[i-1] + C[i];
  foreach(immutable int i; 0 .. N)
    costd[i] = cos[i].to!double / (i+1);

  ans += cos[N-1];

  if(N >= V) {
    writeln(ans);
    return;
  }

  int num = V - N;

  void tc(int n) {
    double minc = double.max;
    int mincp;
    foreach(immutable int i; 0 .. n) {
      if(minc > costd[i]) {
        minc = costd[i];
        mincp = i;
      }
    }

    ++ mincp;

    ans += (num / mincp) * cos[mincp-1];
    //writeln("~", mincp, "(", cos[mincp-1], ")", "*", num / mincp, "=>", ans);
    num %= mincp;
  }

  tc(N);
  while(num != 0) {
    tc(num);
  }

  writeln(ans);
}