View Compilation Error

0_0_19088987_2635.cpp:4:7: error: 'maxn' was not declared in this scope
 int a[maxn];
       ^
0_0_19088987_2635.cpp: In function 'int main()':
0_0_19088987_2635.cpp:13:16: error: 'a' was not declared in this scope
    scanf("%d",&a[i]);
                ^
0_0_19088987_2635.cpp:17:7: error: 'a' was not declared in this scope
    if(a[i]==temp) temp--;
       ^