In function 'void loop()': 17:6: error: expected ';' before 'digitalWrite' 23:5: error: expected ';' before 'digitalWrite' exit status 1

[gcjr]

@achilies018

if (i%2==0)
{
    if (digitalRead (13)==0)
        digitalWrite (3,HIGH);
    else (digitalRead (13)==1)
        digitalWrite (3,HIGH);
}

i think you intended

    if (i%2==0)
    {
        if (digitalRead (13)==0)
            digitalWrite (3,HIGH);
        else if (digitalRead (13)==1)
            digitalWrite (3,HIGH);
    }

but if the if condition is NOT true, the else is the NOT cond

    if (i%2==0)
    {
        if (digitalRead (13)==0)
            digitalWrite (3,HIGH);
        else
            digitalWrite (3,HIGH);
    }

but looks like both the if and else do the same thing, so you probably intended

    if (i%2==0)
    {
        if (digitalRead (13)==0)
            digitalWrite (3,HIGH);
        else
            digitalWrite (3,LOW);
    }

but this could simple be

    if (i%2==0)
        digitalWrite (3, ! digitalRead (13));