C :

#include<stdio.h>
int main()
{
    char a[3][5]={'a','a','a','a','a','b','b','b','b','b','c','c','c','c','c'};
    int i,j;
    for(i=0;i<3;i++)
    {
        for(j=0;j<5;j++)
            printf("%c",a[i][j]);
            printf("\n");
    }
    return 0;
}

C++ :

#include<iostream>
#include<cstdio>
#include<string>
#include<cmath>
using namespace std;
int main()
{
    cout<<"aaaaa"<<endl<<"bbbbb"<<endl;
    cout<<"ccccc"<<endl;
    return 0;
}