#include <stdio.h>
  static int oppose(int y) {return y*(-1);}
  static int soustraction(int x,int y){ return x+ oppose(y); }
  int main(void){
  int a,b,c;
  printf("Donnez 3 entiers\n");
  scanf("%d %d %d",&a,&b,&c);
  printf("%d\n",soustraction(a,soustraction(b,c)));
  return 0;
  }