/in/foo.cc: In function 'int lca(int, int)':
/in/foo.cc:62:9: warning: unused variable 'ans' [-Wunused-variable]
     int ans=1e9;
         ^~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:108:13: warning: unused variable 'ans' [-Wunused-variable]
         int ans=0;
             ^~~