static int RSF ( int n ) {
  while ( n >= 10 ) {
    int x = n ;
    int l = 0 ;
    while ( n > 0 ) {
      n = n / 10 ;
      l ++ ;
    }
    int a [ ] = new int [ l ] ;
    int i = l - 1 ;
    while ( x > 0 ) {
      a [ i ] = x % 10 ;
      x = x / 10 ;
      i -- ;
    }
    for ( int j = 0 ;
    j < l - 1 ;
    j ++ ) {
      n = n * 10 + Math . abs ( a [ j ] - a [ j + 1 ] ) ;
    }
  }
  return n ;
}

static int RSF ( int n ) { while ( n >= 10 ) { int x = n ; int l = 0 ; while ( n > 0 ) { n = n / 10 ; l ++ ; } int a [ ] = new int [ l ] ; int i = l - 1 ; while ( x > 0 ) { a [ i ] = x % 10 ; x = x / 10 ; i -- ; } for ( int j = 0 ; j < l - 1 ; j ++ ) { n = n * 10 + Math . abs ( a [ j ] - a [ j + 1 ] ) ; } } return n ; }
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