/in/foo.cc: In function 'int main()':
/in/foo.cc:24:3: error: 'w_u' was not declared in this scope
   w_u=dp[u];
   ^~~
/in/foo.cc:25:3: error: 'w_v' was not declared in this scope
   w_v=dp[fa[u]];
   ^~~
/in/foo.cc:29:9: error: 'c1' was not declared in this scope
    for (c1=0;c1<c;c1++)
         ^~