C program largest digit of a number

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C

i wrote a program that prints the largest digit of a number

#include <stdio.h>
int main(){
    int num ,  large = 0, rem = 0;
    scanf("%d" , &num);
    while (num > 0) {
                rem = num % 10;

                if (rem > large) {
                        large = rem;
                }

                num = num / 10;
        }

        printf("the biggest digit is %d\n", large);
        return 0;
  }

if working fine but if i input an negative number lets say -432 it prints me 0 , instead of 4. How can i correct that ?

What I have tried:

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