/in/foo.cc: In function 'int main()':
/in/foo.cc:71:46: warning: array subscript is above array bounds [-Warray-bounds]
         LCA[0]=lca(a,b),LCA[1]=lca(a,c),LCA[2]=lca(b,c);
                                         ~~~~~^
/in/foo.cc:79:15: warning: 't' may be used uninitialized in this function [-Wmaybe-uninitialized]
         printf("%d %d\n",t,ans);
         ~~~~~~^~~~~~~~~~~~~~~~~