Main.cc: In function 'int main()':
Main.cc:8:10: error: 'vector' is not a member of 'std'
    8 |     std::vector<std::vector<int>> graph(n, std::vector<int>(m, 0));
      |          ^~~~~~
Main.cc:2:1: note: 'std::vector' is defined in header '<vector>'; did you forget to '#include <vector>'?
    1 | #include <iostream>
  +++ |+#include <vector>
    2 | // Removed 'using namespace std;' to avoid naming conflicts.
Main.cc:8:22: error: 'vector' is not a member of 'std'
    8 |     std::vector<std::vector<int>> graph(n, std::vector<int>(m, 0));
      |                      ^~~~~~
Main.cc:8:22: note: 'std::vector' is defined in header '<vector>'; did you forget to '#include <vector>'?
Main.cc:8:29: error: expected primary-expression before 'int'
    8 |     std::vector<std::vector<int>> graph(n, std::vector<int>(m, 0));
      |                             ^~~
Main.cc:12:13: error: 'graph' was not declared in this scope; did you mean 'isgraph'?
   12 |             graph[x-1][y-1] = v;
      |             ^~~~~
      |             isgraph
Main.cc:13:11: error: 'else' without a previous 'if'
   13 |         } else {
      |           ^~~~
Main.cc:27:23: error: 'prefixSum' was not declared in this scope
   27 |             int ans = prefixSum[x2][y2] - prefixSum[x1-1][y2] - prefixSum[x2][y1-1] + prefixSum[x1-1][y1-1];
      |                       ^~~~~~~~~
Main.cc:32:22: error: 'ans' was not declared in this scope; did you mean 'abs'?
   32 |         std::cout << ans << std::endl;
      |                      ^~~
      |                      abs