#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
#include <math.h>

float dlzka(int x1,int y1,int x2,int y2)
{
      float d;
      d=sqrt(pow((x1-x2),2)+pow((y1-y2),2));
      return(d);
}


main()
{
int a1,a2,b1,b2,n,i;
float ob;
FILE *f;
f=fopen("dlzka.txt","w");
printf("zadaj pocet \n");
scanf("%d",&n);
for(i=1;i<=n;i++){
printf("zadaj suradnice 1.bodu\n");
scanf("%d%d",&a1,&a2);
printf("zadaj suradnice 2.bodu\n");
scanf("%d%d",&b1,&b2);
printf("dlzka usecky  %.2f\n",dlzka(a1,a2,b1,b2));
fprintf(f,"dlzka usecky  %.2f\n",dlzka(a1,a2,b1,b2));

ob= ob+dlzka(a1,a2,b1,b2);}
printf("dlzka je:%.2f\n",ob);
fclose(f);
getch();
}