public static void main ( String [ ] args ) throws IOException {
  BufferedReader br = new BufferedReader ( new InputStreamReader ( System . in ) ) ;
  StringTokenizer st = new StringTokenizer ( br . readLine ( ) ) ;
  int n = Integer . parseInt ( st . nextToken ( ) ) , m = Integer . parseInt ( st . nextToken ( ) ) ;
  int [ ] a = new int [ n ] , b = new int [ m ] ;
  st = new StringTokenizer ( br . readLine ( ) ) ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) a [ i ] = Integer . parseInt ( st . nextToken ( ) ) ;
  st = new StringTokenizer ( br . readLine ( ) ) ;
  for ( int i = 0 ;
  i < m ;
  i ++ ) b [ i ] = Integer . parseInt ( st . nextToken ( ) ) ;
  int i = 0 , j = 0 , cnt = 0 ;
  while ( i < n && j < m ) {
    if ( a [ i ] == b [ j ] ) {
      i ++ ;
      j ++ ;
      cnt ++ ;
    }
    else if ( a [ i ] < b [ j ] ) {
      a [ i + 1 ] = a [ i + 1 ] + a [ i ] ;
      i ++ ;
    }
    else {
      b [ j + 1 ] = b [ j + 1 ] + b [ j ] ;
      j ++ ;
    }
  }
  System . out . println ( cnt ) ;
}

public static void main ( String [ ] args ) throws IOException { BufferedReader br = new BufferedReader ( new InputStreamReader ( System . in ) ) ; StringTokenizer st = new StringTokenizer ( br . readLine ( ) ) ; int n = Integer . parseInt ( st . nextToken ( ) ) , m = Integer . parseInt ( st . nextToken ( ) ) ; int [ ] a = new int [ n ] , b = new int [ m ] ; st = new StringTokenizer ( br . readLine ( ) ) ; for ( int i = 0 ; i < n ; i ++ ) a [ i ] = Integer . parseInt ( st . nextToken ( ) ) ; st = new StringTokenizer ( br . readLine ( ) ) ; for ( int i = 0 ; i < m ; i ++ ) b [ i ] = Integer . parseInt ( st . nextToken ( ) ) ; int i = 0 , j = 0 , cnt = 0 ; while ( i < n && j < m ) { if ( a [ i ] == b [ j ] ) { i ++ ; j ++ ; cnt ++ ; } else if ( a [ i ] < b [ j ] ) { a [ i + 1 ] = a [ i + 1 ] + a [ i ] ; i ++ ; } else { b [ j + 1 ] = b [ j + 1 ] + b [ j ] ; j ++ ; } } System . out . println ( cnt ) ; }
(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 (object_creation_expression type: (type_identifier) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))))) (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_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)))))) (local_variable_declaration type: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier)))) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (expression_statement (assignment_expression left: (identifier) right: (object_creation_expression type: (type_identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))) (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: (expression_statement (assignment_expression left: (array_access array: (identifier) index: (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: (object_creation_expression type: (type_identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))) (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: (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (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: (decimal_integer_literal)) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal)) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (while_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (binary_expression left: (identifier) right: (identifier)))) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (array_access array: (identifier) index: (identifier)))) consequence: (block (expression_statement (update_expression (identifier))) (expression_statement (update_expression (identifier))) (expression_statement (update_expression (identifier)))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (array_access array: (identifier) index: (identifier)))) consequence: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (binary_expression left: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (array_access array: (identifier) index: (identifier))))) (expression_statement (update_expression (identifier)))) alternative: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (binary_expression left: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (array_access array: (identifier) index: (identifier))))) (expression_statement (update_expression (identifier)))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))