long i,t,a,b,c;long g(long p,long q){return q?g(q,p%q):p;}main(s){for(scanf("%d%d%d",&a,&b,&c);i++<4;s=t>s?t:s)t=abs(g(a*b+b*c*(i%2*2-1),a*b+a*c*((i&2)-1)));i=!printf("%ld/%d",i/t,s/(t=g(i=a*b*c,s)));}