第十九題

#include <stdio.h>
int main()
{
while(1)
{
unsigned int x,flag;
printf("請輸入一個正整數:\n");
scanf("%u",&x);
do{
flag=x%2;
x/=10;
}
    while(x&&((!flag)==x%2));
if(x==0)
printf("YES\n");
else
printf("NO\n"); 
}
return 0;

}