View Compilation Error

0_0_38667101_23073.cpp:8:1: error: expected unqualified-id before 'int'
    8 | int sum;
      | ^~~
0_0_38667101_23073.cpp: In function 'void dfs(int, int)':
0_0_38667101_23073.cpp:51:9: error: 'sum' was not declared in this scope
   51 |         sum++;
      |         ^~~
0_0_38667101_23073.cpp: In function 'int main()':
0_0_38667101_23073.cpp:63:9: error: 'sum' was not declared in this scope
   63 |         sum = 0;
      |         ^~~