#include <bits/stdc++.h>
using namespace std;
int fun(int mid,int m){
    int ans=1;
    for(int i=1;i<=m;i++){
        ans=ans*mid;
    }
    return ans;
}
int main()
{
    vector<int>a={0,0,0,0,0,1,1,1};
    int n=a.size();
    int l=0,r=n-1,mid=-1;
    int ans=-1;
    while(l<=r){
        mid=(l+r)/2;
        if(a[mid]==1){
            ans=mid;
            r=mid-1;
        }
        else{
            l=mid+1;
        }
    }
    cout<<"ans "<<ans<<endl;
    return 0;
}