#include <iostream>
using namespace std;

int ikiliArama (int D[ ], int N, int Aranan)
{
    int Ortadaki,Sol=0,Sag=N-1;
    while (Sol<=Sag)
    {
        Ortadaki=(Sol+Sag)/2;
        if(Aranan ==D[Ortadaki])
            return Ortadaki;
        else if(Aranan>D[Ortadaki])
        Sol=Ortadaki+1;
        else
            Sag=Ortadaki-1;
    }
    return -1;
}

int main ( )
{
    int indis, Ara, B[]= {1,2,13,14,15,16,27,38,49,70};
    cout<<"Aranan sayi: ";
    cin>>Ara;
    indis=ikiliArama (B, 10, Ara);
    if (indis ==-1)
        cout<<"Aranan sayi bulunamadi!";
    else
        cout<<"Aranan sayi "<<indis<<" indisli elemandir.\n";

    return 0;
}