是的，而且只有123，这题关键不在数字上
by Sky、 @ 2016-04-18 17:22:45
```cpp
#include <fstream>
using namespace std;
int main()
{
ifstream fin("sort3.in");
ofstream fout("sort3.out");
int count[4],a[4],t[1001],x,n,k=0;
memset(count,0,sizeof(count));
memset(a,0,sizeof(a));
fin>>n;
while (fin>>x) {
count[x]++;
t[++k]=x;
}
for (int i=1;i<=count[1]+count[2];i++){
if (t[i]==3) a[3]++;
else if (t[i]==2&&i<=count[1]) a[1]++;
else if (t[i]==1&&i>count[1]) a[2]++;
}
fout<<a[3]+(a[1]>a[2]?a[1]:a[2])<<endl;
}
//nocow usaco 标程
```
by NicodeX @ 2016-04-19 13:45:22