View Compilation Error

0_0_17063005_28130.cpp:6:7: error: 'maxn' was not declared in this scope
 int A[maxn], B[maxn];
       ^
0_0_17063005_28130.cpp:6:16: error: 'maxn' was not declared in this scope
 int A[maxn], B[maxn];
                ^
0_0_17063005_28130.cpp: In function 'int main()':
0_0_17063005_28130.cpp:11:43: error: 'A' was not declared in this scope
   for(int i = 0; i < n; i++) scanf("%d", &A[i]);
                                           ^
0_0_17063005_28130.cpp:12:43: error: 'B' was not declared in this scope
   for(int i = 0; i < m; i++) scanf("%d", &B[i]);
                                           ^
0_0_17063005_28130.cpp:13:8: error: 'A' was not declared in this scope
   sort(A, A + n); sort(B, B + m);//排序
        ^
0_0_17063005_28130.cpp:13:24: error: 'B' was not declared in this scope
   sort(A, A + n); sort(B, B + m);//排序
                        ^