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(b*(i%2?a+c:a-c),a*(i&2?b+c:b-c)));i=!printf("%ld/%d",i/t,s/(t=g(i=a*b*c,s)));}