#include <iostream>
using namespace std;
 
int sqrt(int x){
        long long start, end, mid;
        start=0;end=x;
        if(x==1){return 1;}
        mid = end;
        while((end-start)>1){
            mid = start + (end-start)/2;
            cout << start << " " << end << " " << mid << " " << endl; 
            if(mid*mid==x){
                return mid;
            }
            else if(mid*mid<x){
                start=mid;
            }
            else{
                end=mid;
            }
        }
        if(mid*mid<x){return mid;}
        else{return start;}
    }
 
int main() {
	// your code goes here
	cout << sqrt(2147395599) << endl;
	return 0;
}

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