#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int  die      (char * a) { printf(a);   exit(1);                                            }
char saturate (char a)   { return a * !((a - 1) & ~7);                                      }
char hi_nibble(char a)   { return a >> 4;                                                   }
char lo_nibble(char a)   { return a & 15;                                                   }
char valid    (char a)   { return hi_nibble(a) && lo_nibble(a);                             }
int  perevod  (char * a) { return saturate(a[0] - 'A' + 1) << 4 | saturate(a[1] - '1' + 1); }
#define BUFLEN 255
int main()
{
    char s[BUFLEN];
    fgets(s, BUFLEN, stdin);
    int z1, z2;
    z1=perevod(s);
    z2=perevod(s + 3);
    (strlen(s) != 6 || !valid(z1) || !valid(z2) || s[2] != '-') && die("ERROR");
    abs(hi_nibble(z1) - hi_nibble(z2)) + abs(lo_nibble(z1) - lo_nibble(z2)) == 3 ? printf("YES") : printf("NO");
    return 0;
}

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

QTEtQjM=

A1-B3