#include <stdio.h>  
int n,m,i,j,d,k,v[1000009],a[10009],b[10009],c[10009];  
   
int cmmmc(int a, int b)   
 {int r,q,w;  
 q=a;w=b;  
 while(b!=0)    
    {r=a%b;    
     a=b;    
     b=r;}    
 return ((q*w)/a);    
 }    
   
 int main()  
 {  
  
  freopen("oz.in","r",stdin);  
  freopen("oz.out","w",stdout);  
  scanf("%d %d",&n,&m);  
  for (k=1;k<=n;k++) v[k]=1;  
  for (k=1;k<=m;k++)  
   {scanf("%d %d %d",&a[k],&b[k],&c[k]);  
    v[a[k]]=cmmmc(v[a[k]],c[k]);  
   v[b[k]]=cmmmc(v[b[k]],c[k]);  
   }  
  
  /*for (k=1;k<=m;k++)  
   
  for (k=1;k<=n;k++) printf("%d ",v[k]);  */
   printf("-1");
   return 0;}