#include <bits/stdc++.h>   using namespace std;   static const double EPS = 1e-9;   static const double PI = acos(-1.0);   char ans[4][110];   int main() {     int n;     while (scanf( %d , &n) > 0) {       if (n == 1) {         printf( a na nb nb n );         continue;       }       ans[0][0] =  a ;       ans[1][0] =  a ;       ans[2][0] =  b ;       ans[3][0] =  c ;       int ud = 2;       char p =  b ;       for (int i = 1; i < n; i++) {         ans[ud][i] = p;         ans[ud + 1][i] = p + 1;         p += 2;         if (p >=  x ) {           p =  a ;         }         ud ^= 2;         if (i == n - 1) {           ans[ud][i] = p;           ans[ud + 1][i] = p;         } else {           ans[ud][i] = p;           ans[ud + 1][i] = p + 1;         }       }       for (int y = 0; y < (int)(4); y++) {         for (int x = 0; x < (int)(n); x++) {           putchar(ans[y][x]);         }         puts(  );       }     }   }   