#include <stdio.h>

int main ()
{
  float a11, a12, a21, a22;
  float resenje;
  
  printf ("Unesite matricu: ");
  scanf ("%f%f%f%f", &a11, &a12, &a21, &a22);
  
  resenje = (a11*a22) - (a12*a21);
  
  printf ("%4f\n", resenje);
  
  return 0;
}

