#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define ld long double
#define pii pair<int,int>
#define vi vector<int>
#define si set<int>
#define qi queue<int>
#define sti stack<int>
#define fi first
#define se second
#define pb push_back
#define clr(f,n) memset(f,0,sizeof(int)*(n))
#define cpy(f,g,n) memcpy(f,g,sizeof(int)*(n))
const int N=1000+5;
int n,m,d;
unordered_map<int,int>s[2];
int a[N],tot=0;
void mul(int x,int id){
    for (int i=2;i*i<=x;i++){
        if (x%i==0){
            while(x%i==0){
                s[id][i]++;x/=i;
            }
        }
    }
    if (x!=1)s[id][x]++;
    return ;
}
int f[N*N],tp;
void px(int x){
    int jw=0;
    for (int i=1;i<=tp;i++){
        f[i]=f[i]*x+jw;
        jw=f[i]/10;f[i]%=10;
    }
    while(jw){
        f[++tp]=jw%10;jw/=10;
    }
}
int main(){
	freopen ("bag.in","r",stdin);
	freopen ("bag.out","w",stdout);
	scanf("%d%d%d",&n,&m,&d);
	for (int i=1;i<=n;i++){
	    scanf("%d",&a[i]);tot+=a[i];
    }
    for (int i=1;i<=m;i++){
        int x,y;scanf("%d%d",&x,&y);
        mul(a[y],0);mul(tot,1);
        a[y]+=d;tot+=d;
    }
    unordered_map<int,int>::iterator it;
    for (it=s[0].begin();it!=s[0].end();it++){
        int x=it->first,y=it->second,z=s[1][x];
        if (z){
            s[0][x]-=min(y,z);s[1][x]-=min(y,z);
        }
    }
    memset(f,0,sizeof(f));
    f[1]=1;tp=1;
    for (it=s[0].begin();it!=s[0].end();it++){
        int x=it->first,y=it->second;
        if (!y)continue;
        for (int j=1;j<=y;j++)px(x);
    }
    for (int i=tp;i>=1;i--)printf("%d",f[i]);
    printf("/");
    memset(f,0,sizeof(f));
    f[1]=1;tp=1;
    for (it=s[1].begin();it!=s[1].end();it++){
        int x=it->first,y=it->second;
        if (!y)continue;
        for (int j=1;j<=y;j++)px(x);
    }
    for (int i=tp;i>=1;i--)printf("%d",f[i]);
    printf("\n");
}