View Compilation Error

0_0_30102394_5602.cpp:9:8: error: conflicting declaration 'int maxn'
 int T, maxn, cnt;
        ^
0_0_30102394_5602.cpp:6:11: note: previous declaration as 'const int maxn'
 const int maxn = 650;
           ^
0_0_30102394_5602.cpp: In function 'void init()':
0_0_30102394_5602.cpp:17:18: error: 'n' was not declared in this scope
      scanf("%d",&n);
                  ^