View Compilation Error

0_0_38264208_20029.cpp: In function 'int main()':
0_0_38264208_20029.cpp:28:9: error: expected unqualified-id before '[' token
    auto [a,b,w] = edges[i];
         ^
0_0_38264208_20029.cpp:29:19: error: 'a' was not declared in this scope
    int ra = find (a),rb = find (b);
                   ^
0_0_38264208_20029.cpp:30:14: error: 'rb' was not declared in this scope
    if (ra != rb) {
              ^
0_0_38264208_20029.cpp:33:12: error: 'w' was not declared in this scope
     ans += w;
            ^