diff --git a/Customising the track.cpp b/Customising the track.cpp
new file mode 100644
index 0000000..473ef1f
--- /dev/null
+++ b/Customising the track.cpp	
@@ -0,0 +1,74 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define endl '\n'
+#define Max 1022
+#define mod 1000000007
+#define ll long long int
+#define ld long double
+#ifndef ONLINE_JUDGE
+#define debug(x) cerr << #x << " = " << x << endl;
+#else
+#define debug(x)
+#endif
+#define cel(x, a) (((x) + (a)-1) / (a))
+#define deb(x) cout << #x << '=' << x << endl
+#define deb2(x, y) cout << #x << '=' << x << ',' << #y << '=' << y << endl
+#define deb3(x, y, z)                                                        \
+    cout << #x << '=' << x << ',' << #y << '=' << y << ',' << #z << '=' << z \
+         << endl
+#define pf(a, b) cout << fixed << setprecision(b) << a << '\n'
+typedef pair<int, int> pii;
+typedef pair<ll, ll> pl;
+typedef vector<int> vi;
+typedef vector<ll> vl;
+typedef vector<pii> vpii;
+typedef vector<pl> vpl;
+typedef vector<vi> vvi;
+typedef vector<vl> vvl;
+#define F first
+#define S second
+#define pb push_back
+#define pob pop_back()
+#define mp make_pair
+#define fio ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL)
+#define all(s) (s).begin(), (s).end()
+ll mult(ll a, ll b, ll p = mod) { return ((a % p) * (b % p)) % p; }
+ll add(ll a, ll b, ll p = mod) { return (a % p + b % p) % p; }
+template <typename T, typename U>
+static inline void amin(T &x, U y) {
+    if (y < x) x = y;
+}
+template <typename T, typename U>
+static inline void amax(T &x, U y) {
+    if (x < y) x = y;
+}
+template <typename T>
+void printV(vector<T> v) {
+    cerr << "[ ";
+    for (T i : v) cerr << i << " ";
+    cerr << "]\n";
+}
+
+void solve() {
+    ll n;
+    cin >> n;
+    vl a(n);
+    ll sum = 0;
+    for (ll i = 0; i < n; i++) cin >> a[i], sum += a[i];
+    ll c = sum % n;
+    ll rem = n - c;
+    cout << rem * c << endl;
+}
+
+int main() {
+    fio;
+#ifndef ONLINE_JUDGE
+    freopen("Error.txt", "w", stderr);
+#endif
+    ll t = 1;
+    cin >> t;
+    while (t--) {
+        solve();
+    }
+    return 0;
+}
\ No newline at end of file