#include <stdio.h>

float RectArea(float length, float width);

int
main()
{
    float x, y, area;
    printf("Length, width: ");
    scanf("%g, %g", &x, &y);
    area = RectArea(x, y);
    printf("Area = %g\n", area);
    return 0;
}

float
RectArea(float length, float width)
{
    return length * width;
}