fl.c

#include <math.h>
#include <stdio.h>
 
int main()
{
    int n, dummy;
 
    while (scanf("%d/%d", &dummy, &n) == 2) {
        int x, y, cnt = 0;
        x = y = 2 * n;
 
        while (y > n) {
            double res = ((double) x / (x + y)) * y;
            if (res == n) {
                //printf("1/%d + 1/%d = 1%d\n", x, y, n);
                cnt++;
                x++;
            } else if (res > n) {
                int newy = floor(((double) x / (x - n)) * n);
                if (newy < y) {
                    y = newy;
                } else {
                    break;
                }
            } else {
                int newx = ceil(((double) y / (y - n)) * n);
                if (newx > x) {
                    x = newx;
                } else {
                    break;
                }
            }
        }
        printf("%d\n", cnt);
    }
 
    return 0;
}