/in/foo.cc: In function 'void build(long long int, long long int, long long int)':
/in/foo.cc:49:17: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
     int mid = l + r >> 1;
               ~~^~~
/in/foo.cc: In function 'long long int querygcd(long long int, long long int, long long int)':
/in/foo.cc:73:44: warning: unused variable 'ans' [-Wunused-variable]
     int mid = (tree[p].l + tree[p].r) >> 1,ans = 1;
                                            ^~~