#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
int gcm(int a, int b)
{
if(a < 0) a = -a;
if(b < 0) b = -b;
while(b>0) {
int tmp = a % b;
a = b;
b = tmp;
}
return a;
}
class stick
{
public:
int len0;
int len1;
stick *child0;
stick *child1;
stick *parent;
int min_weight()
{
int weight0 = 1;
if(child0 != NULL) {
weight0 = child0->min_weight();
}
int weight1 = 1;
if(child1 != NULL) {
weight1 = child1->min_weight();
}
int moment0 = weight0 * len0;
int moment1 = weight1 * len1;
int moment_gcm = gcm(moment0, moment1);
int mul0 = moment1 / moment_gcm;
int mul1 = moment0 / moment_gcm;
return weight0 * mul0 + weight1 * mul1;
}
stick() : len0(0), len1(0), child0(NULL), child1(NULL), parent(NULL)
{
}
~stick()
{
}
};
int main(int argc, char *argv[], char *envp[])
{
#ifdef DEBUG
FILE *in = stdin;
FILE *out = stdout;
#else
FILE *in = fopen("input.txt", "r");
FILE *out = fopen("output.txt", "w");
#endif
int n;
fscanf(in, "%d\n", &n);
vector<stick> sticks(n);
for(int i=0;i<n;i++) {
int p;
int q;
int r;
int b;
fscanf(in, "%d %d %d %d\n", &p, &q, &r, &b);
sticks[i].len0 = p;
sticks[i].len1 = q;
if(r != 0) {
sticks[i].child0 = &sticks[r-1];
sticks[r-1].parent = &sticks[i];
}
if(b != 0) {
sticks[i].child1 = &sticks[b-1];
sticks[b-1].parent = &sticks[i];
}
}
stick *root = &sticks[0];
while(root->parent != NULL) {
root = root->parent;
}
fprintf(out, "%d\n", root->min_weight());
fclose(in);
fclose(out);
return 0;
}
