#include <iostream>

void linearSearch(int *A, int length,int v){
    int i=-1;

    for(int j=0; j<length; j++)
        if(v==A[j])
            i=j;

    if(i!=-1)
        std::cout<<i;
    else
        std::cout<<"NIL";
}

int main(){
    int A[5] = {2,4,6,8,10};
    int length = sizeof(A)/sizeof(*A);
    linearSearch(A, length,7);
}