#include #define REP(i,a,b) for(i=a;i 0) { if(n&1) res = res * x; x = x * x; n >>= 1; } return res; } int main(void) { int i,j; int n; ull start,end; scanf("%d",&n); scanf("%llu",&start); rep(i,n-1) scanf("%llu",&end); printf("%llu/%llu",end,start); return 0; }