function main(input) {
  var inputArr = input.split(/\r?\n/).map(inp => inp.split(" "));
  var ranking = inputArr[1].map(vote => parseInt(vote)).sort().reverse();
  var m = inputArr[0][1]
  var idx = m - 1;
  var popular = ranking[idx];
  var totalVotes = ranking.reduce((total, vote) => total + vote);
  
 for(var i = 0; i < m; i++) {
 	if( ranking[i] < 1.0 * totalVotes / m * 4 ) {
    	return false;
    }   
 }
  return true;
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));