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