#include <stdio.h> #include <stdlib.h> int main() { int x; if (scanf("%d", &x) != EOF) { int charnum = 0; char* answer = (char*)malloc(sizeof(char) * x); int answerIdx = 0; while(x != 0) { if(x % 2 == 1) { x--; answer[answerIdx] = charnum + 'a'; answerIdx++; } else { x /= 2; charnum++; } } printf("%s\n", answer); } else { printf("no input\n"); } return 0; }