#include using namespace std; using uint = unsigned int; using ll = long long; using ull = unsigned long long; template using V = vector; template using VV = V>; template using VVV = V>; template using VVVV = VV>; #define rep(i,n) for(ll i=0ll;i bool chmin(T& t, const U& u) { if (t > u){ t = u; return 1;} return 0; } template bool chmax(T& t, const U& u) { if (t < u){ t = u; return 1;} return 0; } void solve(){ ll n,d; cin >> n >> d; string s; rep(i, n) s += "A"; d -= n; for(ll i=n-1; i>=0;i--) if(d){ if(d < 0){ s[i] = 'C'; d++; }else{ s[i] = 'B'; d--; } } cout << s << endl; } int main(){ cin.tie(nullptr); ios::sync_with_stdio(false); int t=1; // cin >> t; rep(i,t) solve(); }