Mine

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv) {
int i;
char s;

if (argc < 3) {
   printf("%s a 5\n", argv[0]);
   return 1;
}

i = atoi(argv[2]);
s = argv[1][0];

while(i) {
   printf("%c\n", s);
   i--;
}

return 0;
}