int main() {
freopen("A.in", "r", stdin);
scanf("%d", &m);
scanf("%d%d", &h.first, &a.first);
scanf("%d%d", &x.first, &y.first);
scanf("%d%d", &h.second, &a.second);
scanf("%d%d", &x.second, &y.second);
std::pair<int, int> rem;
std::pair<int, int> mod;
rem.first = getRem(h.first, a.first, x.first, y.first);
rem.second = getRem(h.second, a.second, x.second, y.second);
mod.first = getRem(a.first, a.first, x.first, y.first);
mod.second = getRem(a.second, a.second, x.second, y.second);
if (rem.first == -1 || rem.second == -1) {
puts("-1");
return 0;
}
if (mod.first == -1 && mod.second == -1) {
if (rem.first == rem.second) printf("%d\n", rem.first);
else puts("-1");
}
else if (mod.first == -1) {
// rem.first = rem.second + k * mod.second
if (rem.first < rem.second || ((rem.first - rem.second) % mod.second)) puts("-1");
else printf("%d\n", rem.first);
}
else if (mod.second == -1) {
if (rem.second < rem.first || ((rem.second - rem.first) % mod.first)) puts("-1");
else printf("%d\n", rem.second);
}
else{
for (int i = 0; i < m; i++) {
long long now = (long long) mod.first * i;
now = (now + rem.first);
map[now] = true;
}
long long answer = 1ll << 50;
for (int i = 0; i < m; i++) {
long long now = (long long)mod.second * i;
now = (now + rem.second);
if (map[now] && answer > now) {
answer = now;
}
}
if (answer == 1ll << 50) puts("-1");
else std::cout << answer << std::endl;
}
return 0;
}
void torus_mapping(void)
{
tw_lpid kpid;
tw_pe * pe;
int nkp_per_pe=16;
for(kpid = 0; kpid < nkp_per_pe; kpid++)
tw_kp_onpe(kpid, g_tw_pe[0]);
int i;
for(i = 0; i < nlp_nodes_per_pe; i++)
{
kpid = i % g_tw_nkp;
pe = tw_getpe(kpid % g_tw_npe);
tw_lp_onpe(i, pe, g_tw_mynode * nlp_nodes_per_pe + i + getRem() );
tw_lp_onkp(g_tw_lp[i], g_tw_kp[kpid]);
tw_lp_settype(i, &nodes_lps[0]);
}
for(i = 0; i < nlp_mpi_procs_per_pe; i++)
{
kpid = i % g_tw_nkp;
pe = tw_getpe(kpid % g_tw_npe);
tw_lp_onpe(nlp_nodes_per_pe+i, pe, N_nodes + g_tw_mynode * nlp_mpi_procs_per_pe + i + getRem() );
tw_lp_onkp(g_tw_lp[nlp_nodes_per_pe + i], g_tw_kp[kpid]);
tw_lp_settype(nlp_nodes_per_pe + i, &nodes_lps[1]);
}
}
tw_lp * torus_mapping_to_lp( tw_lpid lpid )
{
int index;
if(lpid < N_nodes)
index = lpid - g_tw_mynode * nlp_nodes_per_pe - getRem();
else
index = nlp_nodes_per_pe + (lpid - g_tw_mynode * nlp_mpi_procs_per_pe - N_nodes - getRem());
return g_tw_lp[index];
}
