#include <cstdio>
#include <algorithm>
using namespace std;

int main()
{
    double x, y, z;
	scanf( "%lf %lf %lf", &x, &y, &z );

	if ( x > y ) swap( x, y );
	if ( y > z ) swap( y, z );
	
    //if the triangle exists
    if( x + y > z )
    {
        //if it is acute
        double COS_VALUE =  ( x*x + y*y - z*z ) / ( 2*x*y );
        if( COS_VALUE > 0 ) printf( "The triangle is acute." );
        else printf( "The triangle is not acute." );
    }
    else printf( "The triangle doesn't exist." );
    return 0;
}