int pin10 =10;
int pin9 = 9;
int pin8 = 8;
int pin4 = 4;
int a=0;
void setup() 
{
pinMode(pin10, OUTPUT);  
pinMode(pin9, OUTPUT); 
pinMode(pin8, OUTPUT); 
pinMode(pin4, INPUT); 
}
void loop() 
{
if (digitalRead(pin4)==HIGH && a==0)
{
a=1;
}
else 
{
a=0;
}
if (a==1 && digitalRead(pin4)==HIGH)
{
digitalWrite(pin10, HIGH);
delay(1000);
digitalWrite(pin10, LOW);
a=2;
}
else
{
a=0;
}
if (a==2 && digitalRead(pin4)==HIGH)
{
digitalWrite(pin9, HIGH);
delay(3000);
digitalWrite(pin9, LOW);
a=3;
}
else
{
a=0;
}
if (a==3 && digitalRead(pin4)==HIGH)
{
digitalWrite(pin8, HIGH);
delay(2000);
digitalWrite(pin8, LOW);
a=4;
}
else
{
a=0;
}
if (a==4 && digitalRead(pin4)==HIGH)
{
digitalWrite(pin9, HIGH);
delay(2000);
digitalWrite(pin9, LOW);
a=5;
}
else
{
a=0;
}
if (a==5 && digitalRead(pin4)==HIGH)
{
digitalWrite(pin8, HIGH);
delay(2000);
digitalWrite(pin8, LOW);
a=6;
}
else
{
a=0;
}
if (a==6 && digitalRead(pin4)==HIGH)
{
digitalWrite(pin10, HIGH);
delay(2000);
digitalWrite(pin10, LOW);
a=7;
}
else
{
a=0;
}
if (a==7 && digitalRead(pin4)==HIGH)
{
digitalWrite(pin8, HIGH);
delay(2000);
digitalWrite(pin8, LOW);
a=8;
}
else
{
a=0;
}
if (a==8 && digitalRead(pin4)==HIGH)
{
digitalWrite(pin10, HIGH);
delay(1000);
digitalWrite(pin10, LOW);
a=9;
}
else
{
a=0;
}
if (a==9 && digitalRead(pin4)==HIGH)
{
digitalWrite(pin9, HIGH);
delay(3000);
digitalWrite(pin9, LOW);
a=0;
}
}