char c = '3';
int a = int(c);
cout << a;
//51
int a = 3;
char c = char(a);
cout << c;
//'end of text'
string s = "123"
int a = int(s)
//error
s = "234"
a = (int)s
print(a)
//234
a = 4
print(type(a)) //int
a = a/2
print(type(a)) //float
b = 5
b/2 //2.5
a//b : 나눗셈의 몫 -> return int
a%b : 나눗셈의 나머지 -> return int