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


int main() 
{
	
   float a, b, c, x, y;
 
   float e = 0.000001;

   scanf("%f %f %f", &a, &b, &c);

   (a + b > c && a + c > b && b + c > a) ? 

   printf("valid\n") : printf("invalid\n");


   (fabs(a - b) < e && fabs(b - c) < e) ? 

   printf(" equilateral\n") : 

   (fabs(a - b) < e || fabs(b - c) < e || fabs(a - c) < e) ? 

    printf("isosceles\n") : printf("scalene\n");


     x = (a > b) ? ((a > c) ? a:c) : ((b > c) ? b :c);


     y = (x == a) ? b * b + c * c :

         (x == b) ? a * a + c * c : a * a + b * b;


     (fabs(x * x - y) < e) ? printf("right\n") :
  
     (x * x < y) ? printf("acute\n") : printf("obtuse\n");





    

	return 0;
}