KVALIF_VGTU_C

#include <iostream>
#include <cstdio>
#include <math.h>
#include <algorithm>
using namespace std;
int main()
{
    int x[3];
    cin >> x[0] >> x[1] >> x[2];
    sort(x, x+3);
    if( ( x[0] * x[1] ) == ((x[2]) *2) ){cout <<  sqrt( ( x[0] * x[0] ) + ( x[1] * x[1] ) );}
    else if( ( (x[0] * x[0] ) + ( x[1] * x[1] ) ) == sqrt ( x[2] * x[2] ) ){ cout << (x[0] * x[1]) / 2;}
    else if( (sqrt( ( x[2] * x[2] ) - ( x[0] * x[0] ) ) ) == x[1] ){ cout << (x[0] * x[1])/2;}
    else{ cout << ( (x[2]*2)/x[0] );}
    return 0;
}