/in/foo.cc: In function 'int main()':
/in/foo.cc:115:22: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int l=-1,r=n+1,mid=l+r>>1;
                     ~^~
/in/foo.cc:118:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    r=mid,mid=l+r>>1;
              ~^~
/in/foo.cc:120:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    l=mid,mid=l+r>>1;
              ~^~