#include <stdio.h>

extern "C"{
  int logical_shift_left_4(int a);
}

void setup(){
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
    int a;
    printf("Enter an integer to perform 4 times logical shift left: \n");
    scanf("%d", &a);
    int result = logical_shift_left_4(a); 
    printf("Result of logical shift left by 4 bits of %d: %d\n", a, result);  
}