#include <iostream>
using namespace std;
int main(){
int ia ='5' - '0';
int ib ='D' - 'A'+ 10;
char ca = 3 +'0';
char cb = 12-10 +'A';
cout <<“char to int”<< ia << endl;
cout <<“char to int”<< ib << endl;
cout <<“int to char”<< ca << endl;
cout <<“int to char”<< cb << endl;
// 0 ASCII 48
// A ASCII 65
//a ASCII 97
