Classic examples of C language - adding two scores

# include <stdio.h>

int main()
{
	int numerator1, numerator2;// Defining molecules 
	int denominator1, denominator2;// Define denominator 
	int numerator = 0;
	int denominator = 0;

	printf("Please input two fractions(Separate with\",\"): ");
	scanf("%d/%d, %d/%d", &numerator1, &denominator1, &numerator2, &denominator2);

	numerator = numerator1 * denominator2 + numerator2 * denominator1;// The molecule of the last fraction 
	denominator = denominator1 * denominator2;// The denominator of the last fraction 

	printf("result = %d/%d\n", numerator, denominator);

	return 0;
}

  The final result is not the simplest score .