Tunnels

input/code.cpp: In function 'int main()':
input/code.cpp:12:5: error: 'root' was not declared in this scope
     root[i] = i;
     ^

#include <iostream>
#include <stdlib.h>
 
const int MAX_ROOM = 100005;
 
using namespace std;
 
int depc [MAX_ROOM], arrc [MAX_ROOM];
 
int main () {
  for (int i = 0; i < MAX_ROOM; i++) {
    root[i] = i;
  }
  
  int roomc, edgec;
  cin >> roomc >> edgec;
 
  for (int i = 0; i < edgec; i++) {
    int u, v;
    cin >> u >> v;
  
    depc[u]++;
    arrc[v]++;
  }
 
  int ans = 0;
  for (int i = 1; i <= roomc; i++) {
    if (depc[i] > arrc[i]) {
      ans += depc[i] - arrc[i];
    }
  }
 
  cout << max(ans, 1) << endl;
}