#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <string>
using namespace std;
string a[]={"ABC","DEF","GHI","JKL","MNO","PQRS","TUV","WXYZ"};
string c1="QWERTYUIOPASDFGHJKLZXCVBNM",c2="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
char hash[128];
int main(int argc, char** argv) {
	
    char s[1001],b[1001],ans[1001];
    int i,j,len,tmp;
//   	freopen("1008.in","r",stdin);
//   	freopen("1008.out","w",stdout);
    for (i=0;i<26;i++)
        hash[c1[i]]=c2[i];
    while (gets(s))
    {
        for (i=j=0;s[i];i+=2,j++)
            b[j]=hash[a[s[i]-'2'][s[i+1]-'1']];
        b[j]=0;
		ans[j]=0;
        len=j/2+(j&1);
        ans[j-1]=b[len-1];
        tmp=i=0;j=len;
        
        while (b[j])
        {
            ans[tmp++]=b[i++];
            ans[tmp++]=b[j++];
        }
		
        puts(strrev(ans));
    }
    return (EXIT_SUCCESS);
}