#include<stdio.h> #include<iostream> using namespace std;  int main() {     string table[] = {"abcd","efgh","ijkl","mnop"};     for (int c = 0; c <= 4; c++)     {         for(int r = 0; r<= 4; r++)         {             string word = word + table[c][r];             cout<<word;         }     } }