void setup() {
  pinMode(A0,INPUT);
  Serial.begin (9600);
}
float val;

void loop() {
  // put your main code here, to run repeatedly:
val=analogRead(A0);
float milivolt = (val/1024.0) * 5000;
float kelvin= (millivolt/10);
float celsius= kelvin - 273.15;
Serial.println(celsius);
}