#include<cstdio>

int main(){
	double x[4], y[4];
	int xi[4], yi[4];
	while(1 + 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])){
		for(int j = 0; j < 4; j++){
 			xi[j] = (int)(x[j] * 100000);
			yi[j] = (int)(y[j] * 100000);
		}
		
		if((yi[0] - yi[1])*(xi[2] - xi[3]) == -(xi[0] - xi[1])*(yi[2] - yi[3]) && ((yi[0] - yi[1])*(xi[2] - xi[3]))){
			printf("YES\n");
		}else if ( (!(xi[0] - xi[1]) && !(yi[2] - yi[3])) || (!(yi[0] - yi[1]) && !(xi[2] - xi[3]))){
			printf("YES\n");
		}else{
			printf("NO\n");
		}
	}
	return 0;
}