/in/foo.cc: In function 'int dfs(int)':
/in/foo.cc:28:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:41:7: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
    if (b[i-1]==g[b[i]][0]) if (g[b[i]][1]!=b[1]) {
       ^
/in/foo.cc:77:7: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
    if (b[i-1]==g[b[i]][0]) if (g[b[i]][1]!=b[1]) {
       ^