#include <stdio.h>

int main(void)
{
	double x[4],y[4];
	while(scanf("%lf %lf %lf %lf %lf %lf %lf %lf", &x[0], &y[0], &x[1], &y[1], &x[2], &y[2], &x[3], &y[3]) != EOF){
		if(y[1] == y[0]){
			if(x[3] == x[2]){
				printf("YES\n");
			}else{
				printf("NO\n");
			}
		}else if(x[1] == x[0]){
			if(y[3] == y[2]){
				printf("YES\n");
			}else{
				printf("NO\n");
			}
		}else if((x[1] - x[0]) * (y[3] - y[2]) == -(x[3] - x[2]) * (y[1] - y[0])){
			printf("YES\n");
		}else{
			printf("NO\n");
		}
	}
	return 0;
}