public static void main ( String [ ] args ) throws IOException {
  FastScanner input = new FastScanner ( ) ;
  long a = input . nextLong ( ) ;
  long b = input . nextLong ( ) ;
  long c = input . nextLong ( ) ;
  long ans = 0 ;
  ans = ( a * b * c ) - ( ( a - 1 ) * ( b - 1 ) * ( c - 1 ) ) ;
  System . out . println ( ans ) ;
}

public static void main ( String [ ] args ) throws IOException { FastScanner input = new FastScanner ( ) ; long a = input . nextLong ( ) ; long b = input . nextLong ( ) ; long c = input . nextLong ( ) ; long ans = 0 ; ans = ( a * b * c ) - ( ( a - 1 ) * ( b - 1 ) * ( c - 1 ) ) ; System . out . println ( ans ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) (throws (type_identifier)) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_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)))) (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)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (identifier))) right: (parenthesized_expression (binary_expression left: (binary_expression left: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal)))) right: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal)))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))