View Compilation Error

0_0_22092378_21834.cpp: In function 'int main()':
0_0_22092378_21834.cpp:3:9: error: 'ktl' was not declared in this scope
     ktl();
         ^
0_0_22092378_21834.cpp:5:24: error: 'scanf' was not declared in this scope
     while(scanf("%d",&n)!=EOF)
                        ^
0_0_22092378_21834.cpp:5:27: error: 'EOF' was not declared in this scope
     while(scanf("%d",&n)!=EOF)
                           ^
0_0_22092378_21834.cpp:7:19: error: 'a' was not declared in this scope
         for(int i=a[n][0];i>0;i--)
                   ^
0_0_22092378_21834.cpp:9:32: error: 'printf' was not declared in this scope
             printf("%d",a[n][i]);
                                ^
0_0_22092378_21834.cpp:11:16: error: 'puts' was not declared in this scope
         puts("");
                ^