16:2

#include<bits/stdc++.h>
#define  ll long long
using namespace std;
ll binary_searc(ll arr[],ll n,ll a)
{
           ll l=0,r=n-1;
            ll res=-1;
            while(l<=r)
            {
               ll mid=(l+r)/2;
                if(arr[mid]==a)
                {
                    res=mid;
                    r=mid-1;
                }

                if(arr[mid]<a)
                {

                    l=mid+1;

                }
                else r=mid-1;
            }
            return res;
}
int main()
{
    ll n,q;
    cin>>n>>q;
    ll arr[n];
    for(ll i=0;i<n;i++)
    {
        scanf("%lld",&arr[i]);
    }
    while(q--)
    {
        ll a;
        scanf("%lld",&a);
        printf("%d\n",binary_searc(arr,n,a));
    }

}