#include <stdio.h>
#include <math.h>


int main(void){
	int N,c,p;
	int i;
	char x[2];

	scanf("%d",&N);

	c = 0;
	while(N>0){
		x[0] = 'a' + c%3;
		x[1] = 'a' + c%3+3;
		p = sqrt(N);
		for(i=0;i<p-1;i++){
			printf("%c%c",x[0],x[1]);
		}
		printf("%c",x[0]);
		N = N - p*p;
		c++;
	}
	printf("\n");
}