View Compilation Error

0_0_33210750_19068.cpp: In function 'void update(int, int, int)':
0_0_33210750_19068.cpp:3:19: error: 'maxn' was not declared in this scope
    for(int i=x;i<=maxn;i=i+lowbit(i))
                   ^
0_0_33210750_19068.cpp:3:36: error: 'lowbit' was not declared in this scope
    for(int i=x;i<=maxn;i=i+lowbit(i))
                                    ^
0_0_33210750_19068.cpp:5:5: error: 'c' was not declared in this scope
     c[i][j]=c[i][j]+w;
     ^
0_0_33210750_19068.cpp: In function 'int sum(int, int)':
0_0_33210750_19068.cpp:10:33: error: 'lowbit' was not declared in this scope
     for(int i=x;i>0;i=i-lowbit(i))
                                 ^
0_0_33210750_19068.cpp:13:13: error: 'c' was not declared in this scope
     ans=ans+c[i][j];
             ^