100%AC

#include<cstdio>
#define range(n) for(int i=1;i<=n;i++)
int main(){
    int n,numbers[101],k;
    scanf("%d\n",&n);
    range(n){
        scanf("%d ",&numbers[i]);
    }
    scanf("\n%d",&k);
    range(n){
        if(numbers[i]==k){
            printf("%d",i);
            return 0;
        }
    }
    printf("-1");
}