var input = require('fs').readFileSync('/dev/stdin', 'utf8');
var Arr=(input.trim()).split("\n");
Arr.forEach(function(v){
var arr=v.split(" ").map(Number);
var x="NO";
if(arr[2]-arr[0]!=0 && arr[6]-arr[4]!=0){
var ab=(arr[3]-arr[1])/(arr[2]-arr[0]);
var cd=(arr[3+4]-arr[1+4])/(arr[2+4]-arr[0+4]);
if(ab==cd)x="YES";
}
console.log(x);
});