#include<stdio.h>
int main(){
    int a, b, c;
    printf("Enter the lenghts of the sides of the triangle ( a, b, c): ");
    scanf("%d %d %d ", &a, &b, &c);
    if (a <= 0|| b <=0|| c <= 0){
        printf("Invalid Input\n");
    }
    else{
        if(a==b && b==c){
            printf("Equilateral\n");
        }else if (a==b || b==c || a==c){
            printf("Isosceles\n");
        }else{
            printf("scalene\n");
        }
        return 0;
    }