/in/foo.cc: In function 'int dfs(int)':
/in/foo.cc:30:32: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    ds=rl-nr[to[i]]-wg[i],rl-=ds+1>>1,rr=rl+(ds&1),rs+=ds+1>>1;
                              ~~^~
/in/foo.cc:30:57: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    ds=rl-nr[to[i]]-wg[i],rl-=ds+1>>1,rr=rl+(ds&1),rs+=ds+1>>1;
                                                       ~~^~
/in/foo.cc:31:36: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   else ds=nl[to[i]]-wg[i]-rr,rr+=ds+1>>1,rl=rr-(ds&1),rs+=ds+1>>1;
                                  ~~^~
/in/foo.cc:31:61: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   else ds=nl[to[i]]-wg[i]-rr,rr+=ds+1>>1,rl=rr-(ds&1),rs+=ds+1>>1;
                                                           ~~^~