#include <stdio.h>

int main()  {
	int a,b,c;
	scanf("%d %d %d",&a,&b,&c);
	
	if(a == b && b == c) printf("等边三角形");
	else if(a == b || b == c || a == c) printf("等腰三角形");
	else if(a*a + b*b == c*c || a*a + c*c == b*b || b*b + c*c == a*a) printf("直角三角形");
	else if(a*a + b*b < c*c || b*b + c*c < a*a || c*c + a*a < b*b) printf("钝角三角形");
	else printf("锐角三角形");
	
	return 0;
}