<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def ex_call(func, args):
 """A function-call expression with only positional parameters. The function may be an expression or the name of a function. Each argument may be an expression or a value to be used as a literal. """

    if isinstance(func, str):
        func = ex_rvalue(func)

    args = list(args)
    for i in range(len(args)):
        if not isinstance(args[i], ast.expr):
            args[i] = ex_literal(args[i])

    if sys.version_info[:2] < (3, 5):
        return ast.Call(func, args, [], None, None)
    else:
        return ast.Call(func, args, [])