View Compilation Error

0_0_13780248_28168.cpp: In function 'void update(int, int, int)':
0_0_13780248_28168.cpp:17:19: error: 'maxn' was not declared in this scope
     for(int i=x;i<maxn;i+=lowbit(i))
                   ^
0_0_13780248_28168.cpp:17:35: error: 'lowbit' was not declared in this scope
     for(int i=x;i<maxn;i+=lowbit(i))
                                   ^
0_0_13780248_28168.cpp:20:17: error: 'a' was not declared in this scope
                 a[i][j][k]++;
                 ^
0_0_13780248_28168.cpp: In function 'int sum(int, int, int)':
0_0_13780248_28168.cpp:26:32: error: 'lowbit' was not declared in this scope
     for(int i=x;i>0;i-=lowbit(i))
                                ^
0_0_13780248_28168.cpp:29:22: error: 'a' was not declared in this scope
                 res+=a[i][j][k];
                      ^