public class StringDecode {
	public static void main(String[] args) {
		String a="a2bc3d1";
		StringBuffer b=new StringBuffer();
		StringBuffer c=new StringBuffer();
		for(int i=0;i<a.length();i++){
			if(!(a.charAt(i)>='0' && a.charAt(i)<='9')){
				b.append(a.charAt(i));
			}else{
				int n=a.charAt(i)-'0';
				c.append(add(b,n));
				b.delete(0, b.length());
			}
		}
		System.out.println(c);
	}
	public static StringBuffer add(StringBuffer s,int n){
		StringBuffer s2=new StringBuffer();
		if(n==1){
			return s;
		}else{
			for(int i=0;i<n;i++){
				s2.append(s);
			}
			return s2;
		}
	
	}
}