/in/foo.cc: In function 'void dfs(int, int)':
/in/foo.cc:25:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i=0; i<e[x].size(); i++)if (e[x][i].A!=f)d[e[x][i].A]=e[x][i].B,dfs(x,e[x][i].A);   
               ~^~~~~~~~~~~~
/in/foo.cc: In function 'void dfs1(int, int)':
/in/foo.cc:31:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i=0; i<e[x].size(); i++)if (e[x][i].A!=f){
               ~^~~~~~~~~~~~
/in/foo.cc: In function 'bool ch(long long int)':
/in/foo.cc:61:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i=0; i<e[1].size(); i++)if (can[e[1][i].A])p[++num]=mp(e[1][i].B,e[1][i].A);
               ~^~~~~~~~~~~~