include

using namespace std;

int main(){
int n,t;
int k[10];
cin >> n;
for(int i=0;i<10;i++)
k[i]=-1;
while (n) {
t = n % 10;
if (k[t] == -1) {
k[t] = t;
cout << k[t];
}
n /= 10;
}
}