Why I am getting segmentation fault in test case 4 and 5 ,help me out. this is my code

int main() {

/* Enter your code here. Read input from STDIN. Print output to STDOUT */    
int n,k, c[10000],Bc,sum=0,res,rc;
scanf("%d",&n);
scanf("%d",&k);
for(int i=0;i<n;i++){
    scanf("%d",&c[i]);
sum=sum+c[i];
}

scanf("%d",&Bc);

if((sum-c[k])/2==Bc){
    printf("Bon Appetit");
}
else
   { res=Bc-((sum-c[k])/2);
printf("%d",res);
   }return 0;

}