Main.cc: In function 'int main()':
Main.cc:10:20: error: 'n' was not declared in this scope
for(int i=1;i<=n;i++){
^
Main.cc:13:10: error: 'k' was not declared in this scope
cin>>k;
^
Main.cc:21:5: error: expected ';' before 'return'
return 0;
^
Main.cc:9:15: warning: unused variable 'K' [-Wunused-variable]
long long K,a[1000000];
^