diff --git a/ks1-codechef.cpp b/ks1-codechef.cpp
new file mode 100644
index 0000000..5ad084e
--- /dev/null
+++ b/ks1-codechef.cpp
@@ -0,0 +1,111 @@
+//author:satwik_bhv1
+#include<bits/stdc++.h>
+//datatypes
+#define ll long long
+#define ld long double
+//loops
+#define fr(i,z,n) for(ll i=z;i<n;i++)
+#define br(i,z,n) for(ll i=z;i>n;i--)
+//operations
+#define mp  make_pair
+#define ff 	first
+#define ss 	second
+#define pub push_back
+#define puf push_front
+#define pob pop_back
+#define pof pop_front
+//deque
+#define dki deque <ll>
+#define dkc deque <char>
+//map
+#define mi map<ll, ll>
+#define mf map<ld, ld>
+//vectors
+#define vi vector<ll>
+#define vc vector<char>
+#define vpi vector< pair <ll,ll> >
+#define vpc vector<pair <char,char> > 
+#define vpic vector<pair <ll,char> > 
+#define vpci vector<pair <char,ll> > 
+//constants
+#define pi 3.1415926535897932384626
+#define mod  998244353
+#define llmax 9223372036854775807
+#define llmin -9223372036854775808
+/*notes
+	range of longlong=(-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 )
+	INT_MAX = 2147483647
+	INT_MIN = -2147483648
+*/
+//start
+using namespace std;
+//functions
+void fast() { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); }
+bool sortbysec(const pair<ll, ll>& a, const pair<ll, ll>& b) { return (a.second < b.second); }
+ll sumPairs(vi arr,ll n) 
+{ 
+    ll result = 0; 
+    br(i,n-1,-1)
+    {
+        result += i*arr[i] - (n-1-i)*arr[i]; 
+    }
+    return result-((n*(n-1))/2); 
+} 
+int main()
+{
+	fast();
+	ll t;
+	cin >> t;
+	while (t--)
+	{
+		ll n;
+		cin >> n;
+		vi a,c;
+		vpi b;
+		fr(i, 0, n)
+		{
+			ll w;
+			cin >> w;
+			a.pub(w);
+		}
+		b.pub(mp(0,-1));
+		fr(i, 0, n)
+		{
+		    b.pub(mp((b[i].ff ^ a[i]),i));
+		}
+		sort(b.begin(),b.end());
+		ll ans=0,cnt=0;
+		fr(u,1,b.size())
+		{
+		    vi v;
+		    ll i,k;
+		    while(u<b.size()&&b[u].ff==b[u-1].ff)
+		    {
+		        cnt++;
+		        i=b[u-1].ss+1;
+		        k=b[u].ss;
+		        if(cnt==1)
+		        {
+		            v.pub(i);
+		        }
+		        v.pub(k+1);
+		        u++;
+		    }
+		    if(u>=b.size())
+		    {
+		        ans+=sumPairs(v,v.size());
+		        cnt=0;
+		        //v.clear();
+		        goto lbl;
+		    }
+		    else
+		    {
+		        ans+=sumPairs(v,v.size());
+		        cnt=0;
+		        //v.clear();
+		    }
+		}
+		lbl:cout<<ans<<"\n";
+	}
+	return 0;
+}