# include <stdio.h >
int main()
{
    int a,b,c;
    scanf("%d %d %d",&a,&b,&c);
    if(a<0 || c<0 || a>100 || b>=100 ||c>=100)
    printf("invalid input");
    else if (a==b&&b==c)
    printf ("equilateral");
    else if (a==b||b==c||c==a)
    printf("isosceles");
    else
    printf(" scalene");
    return 0;
}