PID_v1.h not work

// pid_regulator01
#include <PID_v1.h>
#define PIN_INPUT 0
#define PIN_OUTPUT 3
double Setpoint, Input, Output;
double Kp=1, Ki=0.05, Kd=0; 
double Delta;
int i1=1;

 
PID myPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, DIRECT);

void setup()
{
Input=analogRead(0);
Setpoint = 100; 
myPID.SetMode(AUTOMATIC);
}

void loop()
{
Serial.print('begin');

Input = analogRead(0);
myPID.Compute();

Serial.print('Setpoint=');
Serial.println(Setpoint);

delay(1);
    
    i1++;
} //void loop()

error
character constant too long for its type

Use double quotes for printing, not single.