Error in launch.json under Windows 10

the following code does not work for me under Windows 10 with Visual Studio Code:

```
"args": ["<${fileDirname}//input.txt", ">${fileDirname}//output.txt"],
```
This works though:
```
"args": ["<", "${fileDirname}\\input.txt", ">", "${fileDirname}\\output.txt"],
```