import java.io.*;
import java.util.*;
// @Jasper
public class sol {
static long LINF = (long) 1e18 + 5;
static int INF = (int) 1e9 + 5;
static int MOD = (int) 1e9 + 7;
static int MAX = (int) 3e5 + 5;
static long n, m, ans = 0, a, b;
static long[] plague = new long [MAX];
static long[] root = new long [MAX];
static List <Integer>[] edges = new List[MAX];
static PriorityQueue <Long>[] q = new PriorityQueue [MAX];
public static void dfs(int u){
root[u] = u;
if (u > n){
q[u].add(plague[u]);
q[u].add(plague[u]);
return;
}
for (int v : edges[u]){
dfs(v);
if (q[(int) root[v]].size() > q[(int) root[u]].size())
root[u] = root[v];
}
for (int v : edges[u]){
if (root[u] != root[v]){
while (q[(int) root[v]].size() > 0){
long tmp = q[(int) root[v]].poll();
q[(int) root[u]].add(tmp);
}
}
}
for (int i = 1; i < edges[u].size(); i++)
q[(int) root[u]].poll();
// System.out.println(a + " " + b);
a = q[(int) root[u]].poll();
b = q[(int) root[u]].poll();
a += plague[u];
b += plague[u];
q[(int) root[u]].add(b);
q[(int) root[u]].add(a);
}
//------------------Solution------------------------------------------------
private static void run_case() throws Exception {
n = io.nextInt();
m = io.nextInt();
m += n;
ans = 0;
for (int i = 0; i < MAX; ++i){
edges[i] = new ArrayList <Integer> ();
q[i] = new PriorityQueue <Long> ((x, y) -> Long.compare(y, x));
}
for (int i = 2; i <= m; i++){
a = io.nextInt();
b = io.nextInt();
edges[(int) a].add(i);
plague[i] = b;
ans += b;
}
// System.out.println(ans);
dfs(1);
// System.out.println(a + " " + b);
long tmp = q[(int)root[1]].poll();
a = q[(int)root[1]].peek();
q[(int)root[1]].add((long) 0);
b = 0;
while (q[(int) root[1]].size() > 0){
ans -= (a - q[(int) root[1]].peek()) * b;
b++;
a = q[(int) root[1]].poll();
}
System.out.println(ans);
}
public static void main(String[] args) throws Exception {
int Test = 1;
// Test = io.nextInt();
for (int i = 1; i <= Test; i++){
run_case();
}
io.close();
}
//-----------PrintWriter for faster output---------------------------------
public static FastIO io = new FastIO();
static void sort(int[] a) {
ArrayList<Integer> l = new ArrayList<>();
for (int i : a) l.add(i);
Collections.sort(l);
for (int i = 0; i < a.length; i++) a[i] = l.get(i);
}
public static void swap(int data[], int left, int right) {
int temp = data[left];
data[left] = data[right];
data[right] = temp;
}
public static void reverse(int data[], int left, int right){
while (left < right) {
int temp = data[left];
data[left++] = data[right];
data[right--] = temp;
}
}
public static boolean nextPermutation(int data[]){
if (data.length <= 1)
return false;
int last = data.length - 2;
while (last >= 0) {
if (data[last] < data[last + 1])
break;
last--;
}
if (last < 0)
return false;
int nextGreater = data.length - 1;
for (int i = data.length - 1; i > last; i--) {
if (data[i] > data[last]) {
nextGreater = i;
break;
}
}
swap(data, nextGreater, last);
reverse(data, last + 1, data.length - 1);
return true;
}
//-----------MyScanner class for faster input----------
static class FastIO extends PrintWriter {
private InputStream stream;
private byte[] buf = new byte[1 << 16];
private int curChar, numChars;
// standard input
public FastIO() {
this(System.in, System.out);
}
public FastIO(InputStream i, OutputStream o) {
super(o);
stream = i;
}
// file input
public FastIO(String i, String o) throws IOException {
super(new FileWriter(o));
stream = new FileInputStream(i);
}
// throws InputMismatchException() if previously detected end of file
private int nextByte() {
if (numChars == -1) throw new InputMismatchException();
if (curChar >= numChars) {
curChar = 0;
try {
numChars = stream.read(buf);
} catch (IOException e) {
throw new InputMismatchException();
}
if (numChars == -1) return -1; // end of file
}
return buf[curChar++];
}
// to read in entire lines, replace c <= ' '
// with a function that checks whether c is a line break
public String next() {
int c;
do {
c = nextByte();
} while (c <= ' ');
StringBuilder res = new StringBuilder();
do {
res.appendCodePoint(c);
c = nextByte();
} while (c > ' ');
return res.toString();
}
public String nextLine() {
int c;
do {
c = nextByte();
} while (c < '\n');
StringBuilder res = new StringBuilder();
do {
res.appendCodePoint(c);
c = nextByte();
} while (c > '\n');
return res.toString();
}
public int nextInt() {
int c;
do {
c = nextByte();
} while (c <= ' ');
int sgn = 1;
if (c == '-') {
sgn = -1;
c = nextByte();
}
int res = 0;
do {
if (c < '0' || c > '9')
throw new InputMismatchException();
res = 10 * res + c - '0';
c = nextByte();
} while (c > ' ');
return res * sgn;
}
public long nextLong() {
int c;
do {
c = nextByte();
} while (c <= ' ');
int sgn = 1;
if (c == '-') {
sgn = -1;
c = nextByte();
}
long res = 0;
do {
if (c < '0' || c > '9')
throw new InputMismatchException();
res = 10 * res + c - '0';
c = nextByte();
} while (c > ' ');
return res * sgn;
}
public double nextDouble() {
return Double.parseDouble(next());
}
}
//--------------------------------------------------------
}
Compilation message
fireworks.java:5: error: class sol is public, should be declared in a file named sol.java
public class sol {
^
Note: fireworks.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
1 error
