How to get a character from a string by index in Rust?

I just started learning Rust and encountered a problem that seems very strange to me. In other languages, like Python or JavaScript, I can easily get a character from a string by index: `"hello"[0]` gives me `'h'`. But when I tried to do the same in Rust, the compiler gave an error. Here's my code: ```rust fn main() { let s = String::from("Привет, мир!"); let first = s[0]; // Error! println!("First character: {}", first); } ``` The compiler says something like: "the type `String` cannot be indexed by `{integer}`". I understand that Rust is a safe language, but why can't I just get a character by index? In other languages it works! How do I correctly get a character from a string? What am I doing wrong? I need to process each character of the string individually.