Nested For Loop Help

  2 #include <stdio.h>
  3 #include <stdlib.h>
  4 int main(void)
  5 {
  6     int row;
  7     int ch;
  8     char ch1 = 'F';
  9     for(row=1; row<=6; row++) {
 10         for(ch=1; ch<=row; ch++)
 11
 12             printf("%c", ch1);
 13         printf("\n");
 14     }
 15     return 0;
 16 }