#include<stdio.h>
int main (){
    int n,i,oddfound=0;
    scanf("%d",&n);
    int arr[n];
    for(i=0 ;i<n;i++){
        scanf("%d",&n);
        if (arr[i%2] i=0){
            oddfound=1;
        }
    }
if(oddfound){
    printf("invalid input");
}else{
    for(i=0;i<n;i++){
      if(arr[i]%2 i=0)
      arr[i]=1;
      printf("%d,arr[i]");
    }
}
    return 0;
}