class Solution {
public:
string freqAlphabets(string s) {
int N = s.length();
string ans = "";
for(int i=0;i<N;i++){
if(i+2<N && s[i+2] == '#'){
ans += (s[i]-'0')*10 + s[i+1] - '0' + 'a' - 1;
i+=2;
}else{
ans += s[i] - '1' + 'a';
}
}
return ans;
}
};