#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
using namespace std;
int a[8100],b[8100],n,m,i,j,ans;
int id[30];
void pd()
{
if (n%2==0)
{
for (i=1;i<=26;i++)
if (id[i]%2!=0)
{
printf("Impossible\n");
return 0;
}
}
else
{
int k=0;
for (i=1;i<=26;i++)
if (id[i]%2!=0)
k++;
if (k>1)
{
printf("Impossible\n");
return 0;
}
}
}
void mergesort(int s,int t)
{
}
int main()
{
memset(id,0,sizeof(id));
scanf("%d",&n);
for (i=1;i<=n;i++)
{
char c; c=getchar();
int cc=c-96;
id[cc]++;
a[i]=cc; b[n-i+1]=cc;
}
pd();
mergesort(1,n);
}