void addEdge(Graph G, int u, int v) {
   if((u < 1 && u > getOrder(G) ) || (v < 1 && v > getOrder(G) ) ) {
     printf("Error: Arguments cannont be passed");
     exit(1);
   }
   addArc(G, u, v);
   addArc(G, v, u);
   G->size--;
}

void addArc(Graph G, int u, int v) {
   if((u < 1 && u > getOrder(G) ) || (v < 1 && v > getOrder(G) ) ) {
      printf("Error: Arguments cannot be passed");
      exit(1);
   }
   List L = G->adj[u];
   moveTo(L, 0);
   while(getIndex(L) >= 0){
     if(v <= getElement(L)) {
        break;
     } else {
        moveNext(L);
     }
   }
   if(v <= getIndex(L)) {
     insertBefore(L, v);
   } else {
     append(L, v);
   }
   G->size++;
}