//注释注释
#include<stdio.h>
int main(){
int a,b,c,d;
scanf("%d%d%d",&a,&b,&c);
//sort
if(c<a){
d=a;
a=c;
c=d;
}
if(c<b){
d=c;
c=b;
b=d;
}
if(a>b){
d=b;
b=a;
a=d;
}
if(!(a+b>c)){
printf("Not a triangle");
}
else if(a==c){
printf("Equilateral triangle");
}
else if((a-b)*(b-c)==0){
printf("Isosceles triangle");
}
else printf("Regular triangle");
return 0;
}