#include<stdio.h>
 
 void classify_triangle(int a, int b, int c){
     if (a < 0 || b < 0 || c < 0){
         printf("Invalid Input\n");
     } else {
         if (a == b && b == c) {
             printf("Equilaterial\n");
         } else if (a == b || b == c || a == c) {
             printf("Isosceles\n");
         } else {
             printf("Scalene\n");
         }
     }
 }
 
 int main(){
     int a, b, c;
     printf("Enter three side lenghts: ");
     scanf("%d %d %d", &a, &b, &c);
     classify_triangle(a, b, c);
     return 0;