#include using namespace std; using ll = long long; #define rep(i,m,n) for(int i=m; i bool chmin(T& a, T b){ if(a > b){a = b; return true;} return false; } template bool chmax(T& a, T b){ if(a < b){a = b; return true;} return false; } template T gcd(T a, T b){ return a % b ? gcd(b, a % b) : b; } template T lcm(T a, T b){ return a / gcd(a, b) * b; } int main(){ ios::sync_with_stdio(false); cin.tie(nullptr); string s; cin >> s; int cnt_a = 0; for(char c : s) if(c == 'a') ++cnt_a; rep(i, 0, cnt_a + 1) cout << 'a'; cout << endl; return 0; }