using System; using System.Collections.Generic; using System.Linq; using System.IO; using System.Threading; using System.Text; using System.Text.RegularExpressions; using System.Diagnostics; using static util; using P = pair; class Program { static void Main(string[] args) { var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false }; var solver = new Solver(sw); // var t = new Thread(solver.solve, 1 << 28); // 256 MB // t.Start(); // t.Join(); solver.solve(); sw.Flush(); } } class Solver { StreamWriter sw; Scan sc; void Prt(string a) => sw.WriteLine(a); void Prt(IEnumerable a) => Prt(string.Join(" ", a)); void Prt(params object[] a) => Prt(string.Join(" ", a)); public Solver(StreamWriter sw) { this.sw = sw; this.sc = new Scan(); } public void solve() { long calc_cost(long[] f, long x) { return x * x * f[2] + x * f[1] + f[0]; } int T = sc.Int; for (int _ = 0; _ < T; _++) { int n, m, k; sc.Multi(out n, out m, out k); // var lis = new List[n]; var f = new long[n][]; for (int i = 0; i < n; i++) { f[i] = new long[3]; } for (int i = 0; i < m; i++) { long x, y; sc.Multi(out x, out y); --x; f[x][0] += y * y; f[x][1] -= 2 * y; f[x][2]++; } bool emp = false; var cnt = new long[n]; long cost = 0; for (int i = 0; i < n; i++) { if (f[i][2] == 0) { emp = true; continue; } long b = -f[i][1] / 2; long a = f[i][2]; long q = b % a; long cc; if (q * 2 < b) { cc = b / a; } else { cc = b / a + 1; } cnt[i] = cc; cost += calc_cost(f[i], cc); } long sum = cnt.Sum(); if (sum == k || sum < k && emp) { Prt(cost); continue; } if (sum > k) { long ng = -1, ok = M; while (ng + 1 < ok) { long mid = (ng + ok) / 2; long cc = 0; for (int i = 0; i < n; i++) { if (f[i][2] == 0) continue; long x = Math.Max((-mid - f[i][1] - f[i][2] + 2 * f[i][2] - 1) / (2 * f[i][2]), 0); Assert(x <= cnt[i]); cc += x; } if (cc <= k) { ok = mid; } else { ng = mid; } } { long cc = 0; long ans = 0; for (int i = 0; i < n; i++) { if (f[i][2] == 0) continue; long x = Math.Max((-ok - f[i][1] - f[i][2] + 2 * f[i][2] - 1) / (2 * f[i][2]), 0); Assert(x <= cnt[i]); ans += calc_cost(f[i], x); cc += x; } Assert(k >= cc); ans -= (k - cc) * ok; Prt(ans); } } else { long ng = -1, ok = M; while (ng + 1 < ok) { long mid = (ng + ok) / 2; long cc = 0; for (int i = 0; i < n; i++) { if (f[i][2] == 0) continue; long x = (mid - f[i][1] - f[i][2]) / (2 * f[i][2]); Assert(x >= cnt[i]); cc += x; } if (cc >= k) { ok = mid; } else { ng = mid; } } { long cc = 0; long ans = 0; for (int i = 0; i < n; i++) { if (f[i][2] == 0) continue; long x = (ok - f[i][1] - f[i][2]) / (2 * f[i][2]); Assert(x >= cnt[i]); ans += calc_cost(f[i], x); cc += x; } Assert(k <= cc); ans -= (cc - k) * ok; Prt(ans); } } } } } class pair : IComparable> { public T v1; public U v2; public pair() : this(default(T), default(U)) {} public pair(T v1, U v2) { this.v1 = v1; this.v2 = v2; } public int CompareTo(pair a) { int c = Comparer.Default.Compare(v1, a.v1); return c != 0 ? c : Comparer.Default.Compare(v2, a.v2); } public override string ToString() => $"{v1} {v2}"; public void Deconstruct(out T a, out U b) { a = v1; b = v2; } } static class util { public static readonly int M = 1000000007; // public static readonly int M = 998244353; public static readonly long LM = 1L << 60; public static readonly double eps = 1e-11; public static void DBG(string a) => Console.Error.WriteLine(a); public static void DBG(IEnumerable a) => DBG(string.Join(" ", a)); public static void DBG(params object[] a) => DBG(string.Join(" ", a)); public static void Assert(params bool[] conds) { if (conds.Any(x => !x)) throw new Exception(); } public static pair make_pair(T v1, U v2) => new pair(v1, v2); public static int CompareList(IList a, IList b) where T : IComparable { for (int i = 0; i < a.Count && i < b.Count; i++) if (a[i].CompareTo(b[i]) != 0) return a[i].CompareTo(b[i]); return a.Count.CompareTo(b.Count); } public static bool inside(int i, int j, int h, int w) => i >= 0 && i < h && j >= 0 && j < w; public static readonly int[] dd = { 0, 1, 0, -1 }; // static readonly string dstring = "RDLU"; public static IEnumerable

adjacents(int i, int j) { for (int k = 0; k < 4; k++) yield return new P(i + dd[k], j + dd[k ^ 1]); } public static IEnumerable

adjacents(int i, int j, int h, int w) { for (int k = 0; k < 4; k++) if (inside(i + dd[k], j + dd[k ^ 1], h, w)) yield return new P(i + dd[k], j + dd[k ^ 1]); } public static IEnumerable

adjacents(this P p) => adjacents(p.v1, p.v2); public static IEnumerable

adjacents(this P p, int h, int w) => adjacents(p.v1, p.v2, h, w); public static IEnumerable all_subset(this int p) { for (int i = 0; ; i = i - p & p) { yield return i; if (i == p) break; } } public static Dictionary compress(this IEnumerable a) => a.Distinct().OrderBy(v => v).Select((v, i) => new { v, i }).ToDictionary(p => p.v, p => p.i); public static Dictionary compress(params IEnumerable[] a) => compress(a.SelectMany(x => x)); public static T[] inv(this Dictionary dic) { var res = new T[dic.Count]; foreach (var item in dic) res[item.Value] = item.Key; return res; } public static void swap(ref T a, ref T b) where T : struct { var t = a; a = b; b = t; } public static void swap(this IList a, int i, int j) where T : struct { var t = a[i]; a[i] = a[j]; a[j] = t; } public static T[] copy(this IList a) { var ret = new T[a.Count]; for (int i = 0; i < a.Count; i++) ret[i] = a[i]; return ret; } } class Scan { StreamReader sr; public Scan() { sr = new StreamReader(Console.OpenStandardInput()); } public Scan(string path) { sr = new StreamReader(path); } public int Int => int.Parse(Str); public long Long => long.Parse(Str); public double Double => double.Parse(Str); public string Str => ReadLine.Trim(); public string ReadLine => sr.ReadLine(); public pair Pair() { T a; U b; Multi(out a, out b); return new pair(a, b); } public P P => Pair(); public int[] IntArr => StrArr.Select(int.Parse).ToArray(); public long[] LongArr => StrArr.Select(long.Parse).ToArray(); public double[] DoubleArr => StrArr.Select(double.Parse).ToArray(); public string[] StrArr => Str.Split(new[]{' '}, StringSplitOptions.RemoveEmptyEntries); bool eq() => typeof(T).Equals(typeof(U)); T ct(U a) => (T)Convert.ChangeType(a, typeof(T)); T cv(string s) => eq() ? ct(int.Parse(s)) : eq() ? ct(long.Parse(s)) : eq() ? ct(double.Parse(s)) : eq() ? ct(s[0]) : ct(s); public void Multi(out T a) => a = cv(Str); public void Multi(out T a, out U b) { var ar = StrArr; a = cv(ar[0]); b = cv(ar[1]); } public void Multi(out T a, out U b, out V c) { var ar = StrArr; a = cv(ar[0]); b = cv(ar[1]); c = cv(ar[2]); } public void Multi(out T a, out U b, out V c, out W d) { var ar = StrArr; a = cv(ar[0]); b = cv(ar[1]); c = cv(ar[2]); d = cv(ar[3]); } public void Multi(out T a, out U b, out V c, out W d, out X e) { var ar = StrArr; a = cv(ar[0]); b = cv(ar[1]); c = cv(ar[2]); d = cv(ar[3]); e = cv(ar[4]); } public void Multi(out T a, out U b, out V c, out W d, out X e, out Y f) { var ar = StrArr; a = cv(ar[0]); b = cv(ar[1]); c = cv(ar[2]); d = cv(ar[3]); e = cv(ar[4]); f = cv(ar[5]); } }