求赞！

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll n,q,k,a[100010];
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin>>n>>q;
    for(ll i=1; i<=n; i++) cin>>a[i];
    while(q--) {
        cin>>k;
        ll tmp=lower_bound(a+1,a+n+1,k)-a;
        if(a[tmp]!=k) {
            cout<<-1<<" "<<-1<<"\n";
            continue;
        }
        cout<<tmp-1<<" ";
        tmp=upper_bound(a+1,a+n+1,k)-a;
        cout<<tmp-2<<"\n";
    }
    return 0;
}