/in/foo.cc: In function 'long long int c(long long int)':
/in/foo.cc:32:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
    long long mid=l+r>>1;
                  ~^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:56:18: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   long long mid=l+r>>1;
                 ~^~