【小米oj】硬币排序

#define mm(a) memset(a,0,sizeof(a));
#define max(x,y) (x)>(y)?(x):(y)
#define min(x,y) (x)<(y)?(x):(y)
#define Fopen freopen("1.in","r",stdin); freopen("m.out","w",stdout);
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,b,a) for(int i=(b);i>=(a);i--)
#include<bits/stdc++.h>
typedef long long ll;
#define PII pair<ll,ll>
using namespace std;
const int INF=0x3f3f3f3f;
const int MAXN=(int)2e5 + 5;
const ll mod=1e9+7;

char s[MAXN];
int a,b,c;
int main() {
    scanf("%s",s);
    for(int i=0; s[i]; i++)
        if(s[i]=='a')a++;
        else if(s[i]=='b')b++;
        else c++;
    for(int i=1;i<=a;i++)printf("a");
    for(int i=1;i<=b;i++)printf("b");
    for(int i=1;i<=c;i++)printf("c");
    printf("
");
    return 0;
}