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prog.c - id=11720103 - time::1402157189433 - WRONG ANSWER
#include <stdio.h>
#include <string.h>

int main(){
    char c =' ';
    while(c!='\n'){
        scanf("%c",&c);

        if(c=='A' || c=='B' || c=='C')
            c='2';
        else if(c=='D' || c=='E' || c=='F')
            c='3';
        else if(c=='G' || c=='H' || c=='I')
            c='4';
        else if(c=='J' || c=='K' || c=='L')
            c='5';
        else if(c=='M' || c=='N' || c=='O')
            c='6';
        else if(c=='p' || c=='Q' || c=='R' || c=='S')
            c='7';
        else if(c=='T' || c=='U' || c=='V')
            c='8';
        else if(c=='X' || c=='W' || c=='Y' || c=='Z')
            c='9';

        printf("%c",c);
    }
    return 0;
} /* */

prog.c - id=11720152 - time::1402157249841 - ACCEPTED
#include <stdio.h>
#include <ctype.h>

int main() {
    char ch;
    int dig;
    while ((ch = getc(stdin)) != EOF) {
        if (isalpha(ch)) {
            if (ch >= 'Q') {
                ch--;
            }
            dig = (ch - 'A') / 3;
            putc('2' + dig, stdout);
        } else {
            putc(ch, stdout);
        }
    }
    return 0;
} /* */