public static void main ( String args [ ] ) {
  FastScanner input = new FastScanner ( ) ;
  String s = input . next ( ) ;
  int a [ ] = new int [ 6 ] ;
  for ( int i = 0 ;
  i < s . length ( ) ;
  i ++ ) {
    a [ i ] = s . charAt ( i ) - '0' ;
  }
  int ans = Integer . MAX_VALUE ;
  for ( int i = 0 ;
  i <= 999999 ;
  i ++ ) {
    int temp [ ] = new int [ 6 ] ;
    String s1 = ( String . format ( "%06d" , i ) ) ;
    for ( int j = 0 ;
    j < 6 ;
    j ++ ) {
      temp [ j ] = s1 . charAt ( j ) - '0' ;
    }
    if ( temp [ 0 ] + temp [ 1 ] + temp [ 2 ] != temp [ 3 ] + temp [ 4 ] + temp [ 5 ] ) {
      continue ;
    }
    int count = 0 ;
    for ( int j = 0 ;
    j < 6 ;
    j ++ ) {
      if ( temp [ j ] != a [ j ] ) {
        count ++ ;
      }
    }
    ans = Math . min ( ans , count ) ;
  }
  System . out . println ( ans ) ;
}

public static void main ( String args [ ] ) { FastScanner input = new FastScanner ( ) ; String s = input . next ( ) ; int a [ ] = new int [ 6 ] ; for ( int i = 0 ; i < s . length ( ) ; i ++ ) { a [ i ] = s . charAt ( i ) - '0' ; } int ans = Integer . MAX_VALUE ; for ( int i = 0 ; i <= 999999 ; i ++ ) { int temp [ ] = new int [ 6 ] ; String s1 = ( String . format ( " % 06d " , i ) ) ; for ( int j = 0 ; j < 6 ; j ++ ) { temp [ j ] = s1 . charAt ( j ) - '0' ; } if ( temp [ 0 ] + temp [ 1 ] + temp [ 2 ] != temp [ 3 ] + temp [ 4 ] + temp [ 5 ] ) { continue ; } int count = 0 ; for ( int j = 0 ; j < 6 ; j ++ ) { if ( temp [ j ] != a [ j ] ) { count ++ ; } } ans = Math . min ( ans , count ) ; } System . out . println ( ans ) ; }
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