#include<cstdio>
#include<cstring>
using namespace std;
int c1,c2,z,y,nr,c,i,k,n;
char s1[100],s[100];
int main()
{
    //freopen("input","r",stdin);
    //freopen("output","w",stdout);
    while(1)
    {
        gets(s);
        n=strlen(s)-1;
        z=1;
        nr++;
        i=0;
        while(s[i]!=' ')
        {
            s1[i]=s[i];
            i++;
        }
        s1[i]=0;
        k=i-1;
        c1=s[i+1]-48;
        c2=s[i+3]-48;
        if(c1==0&&c2==0&&s1[0]==48&&s1[1]==0)break;
        else if(nr>1)printf("\n");
        for(i=0;i<=k;i++)
        {
            c=s1[i]-48;
            if(c==c1)s1[i]=c2+48;
        }
        z=0;
        for(i=0;i<=k;i++)
        {
            c=s1[i]-48;
            if(c!=0){z=1;printf("%d",c);}
            else if(c==0&&z==1)printf("0");
        }
        if(z==0)printf("0");
    }
    return 0;
}