C++ :

#include<bits/stdc++.h>
using namespace std;
int n,k,ans,z;
int main()
{
    cin>>n>>k;
    for (int i=1;i<=k;i++)z+=i;
    for (int i=1;i<=n-k;i++)
    {
        z+=k;
//        cout<<z<<endl;
        if (floor(sqrt(z))==sqrt(z))ans+=1;
    }
    cout<<ans;
    return 0;
}