#include <iostream>
#include <string>
bool isTerminal(char symbol) {
return symbol >= 'a' && symbol <= 'z';
}
bool isFirstOfA(const std::string& input) {
if (input.empty()) {
return false;
}
char firstSymbol = input[0];
if (isTerminal(firstSymbol) || firstSymbol == 'A') {
return true;
}
return false;
}
int main() {
std::string input;
std::cout << "Enter a string: ";
std::cin >> input;
if (isFirstOfA(input)) {
std::cout << "The string is in the first of A grammar." << std::endl;
} else {
std::cout << "The string is not in the first of A grammar." << std::endl;
}
return 0;
}