View Compilation Error

0_0_14498775_13666.cpp: In function 'void sub_main()':
0_0_14498775_13666.cpp:247:22: error: 'max_dist' was not declared in this scope
         if (dd[i] == max_dist/2+1 || (max_dist%2==0 && dd[i] == max_dist/2)) {
                      ^