#include<stdio.h>

int main(){
	int p  = 1,minx = 0, maxx = 10000, miny=0,maxy = 10000,i,vysl;
        int p1,p2; 
	while(p){
		scanf("%d\n",&p);
		//printf("%d\n",p);
		maxx = 0;minx = 10000; maxy = 0; miny = 10000;
		for(i = 0; i < p; i++){
			scanf("%d %d\n",&p1,&p2);
			//printf("%d %d\n",p1,p2);
			if(p1 < minx) minx = p1;
			if(p1 > maxx) maxx = p1;
			if(p2 < miny) miny = p2;
			if(p2 > maxy) maxy = p2;
		};
		scanf("%d",&p);
		vysl = (maxx - minx)*2 + (maxy - miny)*2;
	
		printf("The length of the fence will be %d units.\n",vysl);		
	};
	return 0;
}