Simple Timer

I wanna make timer by using 4digit 7 segment but the 'a' in segment doesn't work. I don't know why HELP ME

int a = 1;
int b = 2;
int c = 3;
int d = 4;
int e = 5;
int f = 6;
int g = 7;
int p = 8;
int d4 = 9;
int d3 = 10;
int d2 = 11;
int d1 = 12;
long n = 0;
int x = 100;
int y= 60;
int del = 2500;
void setup()
{
Serial.begin(9600);
pinMode(d1, OUTPUT);
pinMode(d2, OUTPUT);
pinMode(d3, OUTPUT);
pinMode(d4, OUTPUT);
pinMode(a, OUTPUT);
pinMode(b, OUTPUT);
pinMode(c, OUTPUT);
pinMode(d, OUTPUT);
pinMode(e, OUTPUT);
pinMode(f, OUTPUT);
pinMode(g, OUTPUT);
pinMode(p, OUTPUT);
}
void loop()
{
Serial.println("Please Insert Time");
while(Serial.available()==0);
delayMicroseconds(del);
long N=Serial.parseInt();
long i;
for(i=N; i>0; i--){

clearLEDs();
pickDigit(1);
pickNumber((i/y/1000)%10);
delayMicroseconds(del);

clearLEDs();
pickDigit(2);
pickNumber((i/y/100)%10);
delayMicroseconds(del);

clearLEDs();
pickDigit(3);
pickNumber((i/x/10)%10);
delayMicroseconds(del);

clearLEDs();
pickDigit(4);
pickNumber(i/x%10);
delayMicroseconds(del);

}

}

void pickDigit(int x) // 바꿔줄 자리수 출력
{
digitalWrite(d1, LOW);
digitalWrite(d2, LOW);
digitalWrite(d3, LOW);
digitalWrite(d4, LOW);

switch(x)
{
case 1:
digitalWrite(d1, HIGH);
break;
case 2:
digitalWrite(d2, HIGH);
break;
case 3:
digitalWrite(d3, HIGH);
break;
default:
digitalWrite(d4, HIGH);
break;
}
}

void pickNumber(int x) // 표시해줄 숫자 출력
{
switch(x)
{
default:
zero();
break;
case 1:
one();
break;
case 2:
two();
break;
case 3:
three();
break;
case 4:
four();
break;
case 5:
five();
break;
case 6:
six();
break;
case 7:
seven();
break;
case 8:
eight();
break;
case 9:
nine();
break;
}
}

void dispDec(int x) // 표시해줄 DP 위치에 출력
{
digitalWrite(p, LOW);
}

void clearLEDs() // LED clear
{
digitalWrite(a, HIGH);
digitalWrite(b, HIGH);
digitalWrite(c, HIGH);
digitalWrite(d, HIGH);
digitalWrite(e, HIGH);
digitalWrite(f, HIGH);
digitalWrite(g, HIGH);
digitalWrite(p, HIGH);
}

// 숫자 출력 함수들
void zero()
{
digitalWrite(a, LOW);
digitalWrite(b, LOW);
digitalWrite(c, LOW);
digitalWrite(d, LOW);
digitalWrite(e, LOW);
digitalWrite(f, LOW);
digitalWrite(g, HIGH);
}

void one()
{
digitalWrite(a, HIGH);
digitalWrite(b, LOW);
digitalWrite(c, LOW);
digitalWrite(d, HIGH);
digitalWrite(e, HIGH);
digitalWrite(f, HIGH);
digitalWrite(g, HIGH);
}

void two()
{
digitalWrite(a, LOW);
digitalWrite(b, LOW);
digitalWrite(c, HIGH);
digitalWrite(d, LOW);
digitalWrite(e, LOW);
digitalWrite(f, HIGH);
digitalWrite(g, LOW);
}

void three()
{
digitalWrite(a, LOW);
digitalWrite(b, LOW);
digitalWrite(c, LOW);
digitalWrite(d, LOW);
digitalWrite(e, HIGH);
digitalWrite(f, HIGH);
digitalWrite(g, LOW);
}

void four()
{
digitalWrite(a, HIGH);
digitalWrite(b, LOW);
digitalWrite(c, LOW);
digitalWrite(d, HIGH);
digitalWrite(e, HIGH);
digitalWrite(f, LOW);
digitalWrite(g, LOW);
}

void five()
{
digitalWrite(a, LOW);
digitalWrite(b, HIGH);
digitalWrite(c, LOW);
digitalWrite(d, LOW);
digitalWrite(e, HIGH);
digitalWrite(f, LOW);
digitalWrite(g, LOW);
}

void six()
{
digitalWrite(a, LOW);
digitalWrite(b, HIGH);
digitalWrite(c, LOW);
digitalWrite(d, LOW);
digitalWrite(e, LOW);
digitalWrite(f, LOW);
digitalWrite(g, LOW);
}

void seven()
{
digitalWrite(a, LOW);
digitalWrite(b, LOW);
digitalWrite(c, LOW);
digitalWrite(d, HIGH);
digitalWrite(e, HIGH);
digitalWrite(f, HIGH);
digitalWrite(g, HIGH);
}

void eight()
{
digitalWrite(a, LOW);
digitalWrite(b, LOW);
digitalWrite(c, LOW);
digitalWrite(d, LOW);
digitalWrite(e, LOW);
digitalWrite(f, LOW);
digitalWrite(g, LOW);
}

void nine()
{
digitalWrite(a, LOW);
digitalWrite(b, LOW);
digitalWrite(c, LOW);
digitalWrite(d, LOW);
digitalWrite(e, HIGH);
digitalWrite(f, LOW);
digitalWrite(g, LOW);
}

You might expand the number of possible responders by following the instructions in part 7 of this link.

An as-built schematic would be helpful, too. Fritzing is frowned upon, do it by hand if need be.

Pin 1 is used also by the Serial port. This is why segment A fails. You can also use A0, A1 etc. As normal digital pins so use say pin A0 instead of pin 1.

On an UNO, pin 1 is not a good choice as it is used for TX serial.

Use pins 2 through 13.

D14 (A0) through D19 (A5) are also available.

Please edit your post to add code tags ("</>" button on editor).