#include <stdio.h>

void classify_triangle(int a,int b,int c){
    
  if(a < 0 || b < 0 || c < 0) {
      printf("Invalid Input\n");
      return;
  } 
  
  
  if (a + b <= c || a + c <= b || b + c <= a) {
      printf("Invalid Input\n");
      return;
  }
  
  
  if (a == b && b == c) {
      printf("Equilateral\n");
  } else if (a == b || b == c || a ==c){
      printf("Isosceles\n");
  } else {
      printf("Scalene\n");
  }
}