#include <stdio.h>

int main(){
	int a,b,c,tmp;
	while(scanf("%d %d %d",&a,&b,&c) != EOF){
		if(a > b){
			tmp = a;
			a = b;
			b = tmp;
		}
		if(b > c){
			tmp = b;
			b = c;
			c = tmp;
		}
		int aa = a * a, bb = b * b, cc = c * c;
		if(aa + bb == cc)
			printf("直角三角形\n");
		else if(aa + bb > cc)
			printf("锐角三角形\n");
		else
			printf("钝角三角形\n");
	}
	return 0;
}