IntelliJ IDEA LiveTemplate auto increment between usages

Question

I am trying to make my life easier with Live Templates in intelliJ I need to increment some param by 1 every-time I use the snippet.

So I tried to develop some groovyScript, and I am close, but my groovy capabilities keeps me back. the number is not incremented by 1, but incremented by 57 for some reason... (UTF-8?)

here is the script:

File file = new File("out.txt");
int code = Integer.parseInt(file.getText('UTF-8'));
code=code+1;
try{
    if(_1){
        code = Integer.parseInt(_1);
    }
} catch(Exception e){}
file.text = code.toString();
return code

So whenever there's param passed to this script (with _1) the initial value is set, and otherwise simply incremented.

this script needs to be passed to the live template param with:

groovyScript("File file = new File(\"out.txt\");int code = Integer.parseInt(file.getText(\'UTF-8\'));code=code+1;String propName = \'_1\';if(this.hasProperty(propName) && this.\"$propName\"){code = Integer.parseInt(_1);};file.text =code.toString();return code", "<optional initial value>")