#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;
}