// editor2
#include<stdio.h>
#include<string.h>
#include<ctype.h>
char mapping[]={
   "",
   "",
   "ABC",
   "DEF",
   "GHI",
   "JKL",
   "MNO",
   "PQRS",
   "TUV",
   "WXYZ"
   };
   void solve(char*digits,int index,char*current)
   {
   if(digits[index]=='\0'){
   printf("%s",current);
   return;
   }
   int digit=digits[index]-'0';
   char *letters=mapping[digit];
   for (int i=0;letters[i]!='\0';i++){
       current[index]=letters[i];
       solve(digits,index+1,current);
   }
   }
   int main(){
       char digits[105];
       scanf("%s",digits);
       for(int i=0;digits[i]!='\0';i++){
           if(!isdigit(digits[i])||digits[i]<'2'||digits[i]>'9'){
               printf("Invalid Input");
               return 0;
           }
       }
       int len =strlen(digits);
       char current[len + 1];
       current[len]='\0';
       solve(digits,0,current);
       return 0;
   }
           }
       }
   }