How can I reduce code repetition in this C code for PIC microcontroller?

Question

I'm working on this serial communication project with PIC microcontroller. I'm using CCS C For PIC as a programming software. The code works fine right now but I want to improve my programming skills (I am a beginner). Especially these if statements bother me. Because there are too many of them. How can I improve this?

#define bt1 pin_a0
#define bt2 pin_a1
#define bt3 pin_a2
#define bt4 pin_a3
#define bt5 pin_a4
#define bt6 pin_c0
#define bt7 pin_c1
#define bt8 pin_c2
#define bt9 pin_c3
#define bt10 pin_c4
#define bt11 pin_d0
#define bt12 pin_d1
#define bt13 pin_d2
#define bt14 pin_d3
#define bt15 pin_d4
#define enable pin_c5
#define tx pin_c6
#define rx pin_c7

#int_rda
void rda_isr(void)
{
  disable_interrupts(int_rda);
  output_high(pin_d7);
}

void main()
{
  set_tris_a(0xFF);
  set_tris_b(0x00);
  set_tris_c(0xFF);
  set_tris_d(0xFF);
  set_tris_e(0x00);

  output_high(tx);
  output_low(rx);
  output_high(enable);

  enable_interrupts(int_rda);
  enable_interrupts(GLOBAL);

  lcd_init();

  while(TRUE)
  {
    if(input(bt1))     puts("\fbuton 1");
    if(input(bt2))     puts("\fbuton 2");
    if(input(bt3))     puts("\fbuton 3");
    if(input(bt4))     puts("\fbuton 4");
    if(input(bt5))     puts("\fbuton 5");
    if(input(bt6))     puts("\fbuton 6");
    if(input(bt7))     puts("\fbuton 7");
    if(input(bt8))     puts("\fbuton 8");
    if(input(bt9))     puts("\fbuton 9");
    if(input(bt10))     puts("\fbuton 10");
    if(input(bt11))     puts("\fbuton 11");
    if(input(bt12))     puts("\fbuton 12");
    if(input(bt13))     puts("\fbuton 13");
    if(input(bt14))     puts("\fbuton 14");
    if(input(bt15))     puts("\fbuton 15");
  }
}

Answer 1

1. Place your button pins into an array:

const unsigned char pins[] = {bt1, bt2, ... bt_15};

2. Iterate through this array

  while(TRUE)
  {
      for(int index = 1; index <= sizeof(pins); index++)
      {
          if(input(pins[index - 1]))     printf("\fbuton %d", index);
      }
  }