public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int n = Integer . parseInt ( sc . next ( ) ) ;
  int k = Integer . parseInt ( sc . next ( ) ) ;
  int temp0 = Integer . parseInt ( sc . next ( ) ) , temp1 = Integer . parseInt ( sc . next ( ) ) , temp2 = Integer . parseInt ( sc . next ( ) ) ;
  int sum = temp0 + temp1 + temp2 ;
  if ( sum < k ) {
    System . out . println ( 3 ) ;
    sc . close ( ) ;
    return ;
  }
  for ( int i = 4 ;
  i <= n ;
  i ++ ) {
    sum -= temp0 ;
    temp0 = temp1 ;
    temp1 = temp2 ;
    temp2 = Integer . parseInt ( sc . next ( ) ) ;
    sum += temp2 ;
    if ( sum < k ) {
      System . out . println ( i ) ;
      sc . close ( ) ;
      return ;
    }
  }
  System . out . println ( - 1 ) ;
  sc . close ( ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int n = Integer . parseInt ( sc . next ( ) ) ; int k = Integer . parseInt ( sc . next ( ) ) ; int temp0 = Integer . parseInt ( sc . next ( ) ) , temp1 = Integer . parseInt ( sc . next ( ) ) , temp2 = Integer . parseInt ( sc . next ( ) ) ; int sum = temp0 + temp1 + temp2 ; if ( sum < k ) { System . out . println ( 3 ) ; sc . close ( ) ; return ; } for ( int i = 4 ; i <= n ; i ++ ) { sum -= temp0 ; temp0 = temp1 ; temp1 = temp2 ; temp2 = Integer . parseInt ( sc . next ( ) ) ; sum += temp2 ; if ( sum < k ) { System . out . println ( i ) ; sc . close ( ) ; return ; } } System . out . println ( - 1 ) ; sc . close ( ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) 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 (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 (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 (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))))) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))))) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (decimal_integer_literal)))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) (return_statement))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (expression_statement (assignment_expression left: (identifier) right: (identifier))) (expression_statement (assignment_expression left: (identifier) right: (identifier))) (expression_statement (assignment_expression left: (identifier) right: (identifier))) (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))) (expression_statement (assignment_expression left: (identifier) right: (identifier))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (identifier))) consequence: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier)))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) (return_statement))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (unary_expression operand: (decimal_integer_literal))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))