#include<stdio.h>
int main()
{
    int a,b,c;
    scanf("%d %d %d", &a, &b, &c);
    if(a<=0 || b<0 || c<0){
        printf("invaild input");
    }
    else if (a==b && b==c){
        printf("equilateral");
    }
    else if (a == b || b == c || a == c) {
        printf("isosceles");
    }
    eles if{
        printf("scalene");
    }
    return 0;
}