80分求调

#include<stdio.h>
#include<math.h>
int x1,x2,y1,y2,z1,z2;
double e,sum;
double lon(int a, int b ,int c ,int d)
{
    return sqrt((a-c)*(a-c)+(b-d)*(b-d));
}
int main()
{
  scanf("%d%d%d%d%d%d",&x1,&x2,&y1,&y2,&z1,&z2);
  sum=lon(x1,x2,y1,y2)+lon(x1,x2,z1,z2)+lon(y1,y2,z1,z2);
  printf("%.2lf",sum);
  return 0;
}