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