public static void main ( String args [ ] ) {
  Scanner sc = new Scanner ( System . in ) ;
  int t = sc . nextInt ( ) ;
  int cnt = 0 ;
  while ( t -- > 0 ) {
    int a = sc . nextInt ( ) ;
    int b = sc . nextInt ( ) ;
    if ( a < b - 1 ) {
      cnt ++ ;
    }
  }
  System . out . println ( cnt ) ;
}

public static void main ( String args [ ] ) { Scanner sc = new Scanner ( System . in ) ; int t = sc . nextInt ( ) ; int cnt = 0 ; while ( t -- > 0 ) { int a = sc . nextInt ( ) ; int b = sc . nextInt ( ) ; if ( a < b - 1 ) { cnt ++ ; } } System . out . println ( cnt ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (type_identifier) name: (identifier) dimensions: (dimensions))) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (while_statement condition: (parenthesized_expression (binary_expression left: (update_expression (identifier)) right: (decimal_integer_literal))) body: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) consequence: (block (expression_statement (update_expression (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))