int n1stNumber = 0, n2ndNumber = 0;
char szTitle[3];  //这边要Title是定长度的时候会比较安全
char szNumber[2];  //这是用来作atoi转换用的暂存
cin >> szTitle;

strcpy(szNumber, szTitle, 1); //复制第一个字元到szNum
n1stNumber = atoi(szNumber);

strcpy(szNumber, (szTitle+1), 1); //复制第二个字元到szNum
n2ndNumber = atoi(szNumber);

int nResult = n1stNumber * 1 + n2ndNumber * 9;

int nTitle = 0;
cin >> nTitle;

if ( nTitle >99 ) { messagebox( NULL, "The input value is not valid.", 0, 0); };

int n1stNumber = nTitle / 10;
int n2ndNumber = nTitle % 10;

int nResult = n1stNumber * 1 + n2ndNumber *9;