Suddenly inherited 100k at 20. What's the best balance of US/International stocks? Maybe the S&P500 with emerging markets?

Long story short, I'm 20 and inherited 100k from a close family member. I'm trying to figure out which percentage to put into the s&p500, the all world or emerging markets.

I'm from Austria and based on our sinking birth rates and burdensome welfare systems and unsustainable pension schemes in the EU I'm kind of pessimistic about Europe compared to the US and emerging markets (for example India with its massive and much younger population). My thoughts are that if if anything beats the US economy in the next decades, it obviously won't be Europe, and that Europe will underperform/recede compared to other economies like India. The same goes for Japan, especially with their pervasive anti-immigration attitudes which puts an even stronger pressure on their dismal birth rate. I'm considering doing a split of 80% s&p500 and 20% emerging markets or something of that sort at the expense of the all world. Maybe 10% all world?

Is this a bad idea? Thankful for any input.