int floorSqrt(int n)
{
    // Write your code here.
    int low =1,high=n;
    while(low<=high){
        long long mid=(high+low)/2;
        long long val=(mid*mid);
        if(val<=n){
            low=mid+1;
        }
        else{
            high=mid-1;
        }
    }
    return high;
}