for(int i=1,j=0,k;i<=len;){for(;s[i-j-1]==s[i+j+1];j++);rad[i]=j;for(k=1;k<=j && rad[i]-k!=rad[i-k];k++)rad[i+k]=min(rad[i]-k,rad[i-k]);i+=k;j=max(j-k,0);
}

char s[Maxn]={0};
s[0]='*';
for(int i=0;i<_len;i++){s[++len]=_s[i];s[++len]='#';
}
s[len]='&';

#include<iostream>
#include<cstring>
#include<cstdlib>
#include<cstdio>
#include<algorithm>
#define dout printf
using namespace std;const int Maxn=100000+10;
int n,rad[Maxn*2];
int col[Maxn*2],cannot[Maxn*2][30],cnt=0;
int stk[30],top;
bool instk[Maxn*2];
inline void getint(int&x){char c=getchar();for(x=0;!isdigit(c);c=getchar());for(;isdigit(c);c=getchar())x=x*10+c-'0';
}
struct Edge{int b;Edge*next;}edges[Maxn*3*2],*firc[Maxn*2],*fird[Maxn*2];int tot;
void AddEdge(int a,int b,Edge*fir[]){edges[++tot]=(Edge){b,fir[a]};fir[a]=edges+tot;
}
int fa[Maxn*2];
int Find(const int&x){return fa[x]==x?x:fa[x]=Find(fa[x]);
}
bool Union(int x,int y){x=Find(x),y=Find(y);if(x==y)return 0;return fa[y]=x,1;
}
void input(){getint(n);for(int i=1;i<=n;i++)getint(rad[(i<<1)-1]);for(int i=1;i<n;i++)getint(rad[i<<1]);
}void work(const int n2=n*2){int MX_r=1,MX_id=1;char*ans=new char[Maxn];memset(ans,0,sizeof(*ans)*Maxn);for(int i=1;i<=n2;i++)fa[i]=i;for(int i=2;i<=n2;i++){for(int j=max(0, min(MX_r-i,rad[MX_id*2-i]) );i-j>0&&i+j<=n2&&j<=rad[i];j++) {Union(i-j,i+j);}if(rad[i]+i>MX_r)MX_r=i+rad[i],MX_id=i;}for(int f,i=1;f=Find(i),i<=n2;i+=2)AddEdge(f,(i+1)>>1,firc);for(int f1,f2,d,i=2;i<=n2;i++){d=rad[i]+1;f1=Find(i-d),f2=Find(i+d);AddEdge(f1,f2,fird);AddEdge(f2,f1,fird);}for(int x,real,f,i=1;real=(i+1)>>1,i<=n2;i+=2)if(!ans[real]){x=1;f=Find(i);for(;cannot[f][x];x++);for(Edge*p=fird[f];p;p=p->next)cannot[p->b][x]=1;for(Edge*p=firc[f];p;p=p->next)ans[p->b]=x+'a'-1;}puts(ans+1);delete ans;
}
int main(){freopen("password.in","r",stdin);freopen("password.out","w",stdout);input();work();return 0;
}