/in/foo.cc: In function 'int main()':
/in/foo.cc:27:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    mid=L+R>>1;
        ~^~
/in/foo.cc:31:15: error: 're' was not declared in this scope
   else if(t<m)re=mid,R=mid-1;
               ^~