// editor1
#include<stdio.h>
int main()
{
    int a,b,c;
    scanf(%d%d%d,&a&b&c);
    if(a <=0 ||b<=0||c <=0){
        printf("invalid input");
        else if("a==b && b==c"){
            printf("equilat");}
            else if(a==b||b==c||a==c){
                printf("isoceles");
                else{
                    printf("scalence";
                }
                return 0;
                }
            }
            
    }
}