#include <iostream>
#include <string>
#include <functional>
void remove_non_lphabetic_characters(std::string& str) {
str.erase(std::remove_if(str.begin(), str.end(), [](char c) {
return !std::isalpha(c);
}), str.end());
}
int main() {
std::string str = "8go@ c# rust java 123 c &c++.";
remove_non_lphabetic_characters(str);
int result = str.length();
std::cout << result << std::endl;
}
/*
run:
13
*/