int sensoreP = 2;
int motB = 3;
void setup() {
    pinMode(sensoreP, INPUT);
    pinMode(motB, OUTPUT);
}
void loop(){
    digitalWrite(motB, HIGH);
    delay(2000);
    while (digitalRead(sensoreP) == 0) {
        digitalWrite(motB, HIGH);
    }
    digitalWrite(motB, LOW);
    delay(20000);

}