View Compilation Error

0_0_38219447_12457.cpp: In function 'void solve()':
0_0_38219447_12457.cpp:52:8: error: expected unqualified-id before '[' token
   auto [w, x, y] = *st.begin();
        ^
0_0_38219447_12457.cpp:54:17: error: 'x' was not declared in this scope
   int nx = find(x), ny = find(y);
                 ^
0_0_38219447_12457.cpp:55:12: error: 'ny' was not declared in this scope
   if(nx == ny) continue;
            ^
0_0_38219447_12457.cpp:56:10: error: 'w' was not declared in this scope
   ans += w;
          ^
0_0_38219447_12457.cpp:57:12: error: 'ny' was not declared in this scope
   fa[nx] = ny;
            ^