int a = 0;
const int button = 34;
const int A_pin = 21;
const int B_pin = 5;
const int C_pin = 4;
const int D_pin = 16;
const int E_pin = 17;
const int F_pin = 23;
const int G_pin = 22;


void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(button, INPUT);

  pinMode(A_pin, OUTPUT);
  pinMode(B_pin, OUTPUT);
  pinMode(C_pin, OUTPUT);
  pinMode(D_pin, OUTPUT);
  pinMode(E_pin, OUTPUT);
  pinMode(F_pin, OUTPUT);
  pinMode(G_pin, OUTPUT);
}

void loop() {
   if(digitalRead(button)==HIGH){
    a=a+1;
    delay(400);
   }
  if(a==0){
    zero();
  }else if(a==1){
    one();
  }else if(a==2){
    two();
  }else if(a==3){
    three();
  }else if(a==4){
    four();
  }else if(a==5){
    five();
  }else if(a==6){
    six();
  }else if(a==7){
    seven();
  }else if(a==8){
    eight();
  }else if(a==9){
    nine();
  }
  if(a>9){
    a=0;
  }
}

void zero(){
digitalWrite(A_pin, HIGH);
digitalWrite(B_pin, HIGH);
digitalWrite(C_pin, HIGH);
digitalWrite(D_pin, HIGH);
digitalWrite(E_pin, HIGH);
digitalWrite(F_pin, HIGH);
digitalWrite(G_pin, LOW);
}

void one(){

digitalWrite(A_pin, 0);
digitalWrite(B_pin, 1);
digitalWrite(C_pin, 1);
digitalWrite(D_pin, 0);
digitalWrite(E_pin, 0);
digitalWrite(F_pin, 0);
digitalWrite(G_pin, 0);

}

void two(){

digitalWrite(A_pin, 1);
digitalWrite(B_pin, 1);
digitalWrite(C_pin, 0);
digitalWrite(D_pin, 1);
digitalWrite(E_pin, 1);
digitalWrite(F_pin, 0);
digitalWrite(G_pin, 1);

}

void three(){
digitalWrite(A_pin, 1);
digitalWrite(B_pin, 1);
digitalWrite(C_pin, 1);
digitalWrite(D_pin, 1);
digitalWrite(E_pin, 0);
digitalWrite(F_pin, 0);
digitalWrite(G_pin, 1);

}

void four(){
digitalWrite(A_pin, 0);
digitalWrite(B_pin, 1);
digitalWrite(C_pin, 1);
digitalWrite(D_pin, 0);
digitalWrite(E_pin, 0);
digitalWrite(F_pin, 1);
digitalWrite(G_pin, 1);

}

void five(){

digitalWrite(A_pin, 1);
digitalWrite(B_pin, 0);
digitalWrite(C_pin, 1);
digitalWrite(D_pin, 1);
digitalWrite(E_pin, 0);
digitalWrite(F_pin, 1);
digitalWrite(G_pin, 1);
  
}

void six(){

digitalWrite(A_pin, 1);
digitalWrite(B_pin, 0);
digitalWrite(C_pin, 1);
digitalWrite(D_pin, 1);
digitalWrite(E_pin, 1);
digitalWrite(F_pin, 1);
digitalWrite(G_pin, 1);
  
}

void seven(){
digitalWrite(A_pin, 1);
digitalWrite(B_pin, 1);
digitalWrite(C_pin, 1);
digitalWrite(D_pin, 0);
digitalWrite(E_pin, 0);
digitalWrite(F_pin, 0);
digitalWrite(G_pin, 0);
  
}

void eight(){
digitalWrite(A_pin, 1);
digitalWrite(B_pin, 1);
digitalWrite(C_pin, 1);
digitalWrite(D_pin, 1);
digitalWrite(E_pin, 1);
digitalWrite(F_pin, 1);
digitalWrite(G_pin, 1);
  
}

void nine(){
  
 digitalWrite(A_pin, 1);
digitalWrite(B_pin, 1);
digitalWrite(C_pin, 1);
digitalWrite(D_pin, 1);
digitalWrite(E_pin, 0);
digitalWrite(F_pin, 1);
digitalWrite(G_pin, 1);
}