View Compilation Error

0_0_27973498_32476.cpp:7:8: error: 'maxn' was not declared in this scope
 int  a[maxn];
        ^
0_0_27973498_32476.cpp: In function 'int main()':
0_0_27973498_32476.cpp:18:16: error: 'a' was not declared in this scope
    scanf("%d",&a[i]);
                ^
0_0_27973498_32476.cpp:27:11: error: 'a' was not declared in this scope
        if(a[j]<max &&a[j]>0)
           ^