/in/foo.cc: In function 'int main()':
/in/foo.cc:124:25: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
         int mid = l + r + 1 >> 1;
                   ~~~~~~^~~
/in/foo.cc:135:24: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
     printf("%d\n", ans);
                        ^