[Sdoi2013]随机数生成器（BSGS）

#include<map>
#include<cmath>
#include<cstdio>
#include<iostream>
#define ll long long
using namespace std;
inline int read(){
    int x=0;char ch=getchar();
    while(ch<‘0‘||ch>‘9‘)ch=getchar();
    while(ch>=‘0‘&&ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}
    return x;
}
int T;
ll p,a,b,x1,t;
ll exgcd(ll a,ll b,ll &x,ll &y){
    if(!b){x=1;y=0;return a;}
    ll tmp=exgcd(b,a%b,x,y);
    ll t=x;x=y;y=t-a/b*y;
    return tmp;
}
ll fpow(ll a,ll b,ll p){
    ll res=1;
    for(;b;b>>=1,a=a*a%p) if(b&1) res=res*a%p;
    return res;
}
map<ll,int> mp;
ll BSGS(ll A,ll B,ll C){
    A%=C;
    if(!A){
        if(!B)return 1;
        return -1; 
    }
    ll m=sqrt(C)+1,t=1,I=1,Im=fpow(A,C-1-m,C);
    mp.clear();mp[1]=m+1;
    for(int i=1;i<m;i++){
        t=t*A%C;
        if(!mp[t])mp[t]=i;
    }
    for(int k=0;k<m;k++){
        int i=mp[B*I%C];
        if(i){
            if(i==m+1)i=0;
            return k*m+i;
        }
        I=I*Im%C;
    }
    return -1;
}
ll cal1(){
    ll C=(t-x1+p)%p,x,y;
    ll t=exgcd(b,p,x,y);
    if(C%t)return -1;C/=t;
    x=x*C%p;
    if(x<0)x+=p;
    return x+1;
}
ll cal2(){
    ll c=fpow(a-1,p-2,p),A=(x1+b*c)%p,C=(t+b*c)%p,x,y;
    ll t=exgcd(A,p,x,y);
    if(C%t)return -1;C/=t;
    if(x<p)x=x%p+p;
    t=BSGS(a,x*C%p,p);
    if(t!=-1)return t+1;
    return -1;
}
ll solve(){
    if(x1==t)return 1;
    if(a==0){
        if(b==t)return 2;
        return -1;
    }
    if(a==1)return cal1();
    else return cal2();
}
int main(){
    T=read();
    while(T--){
        p=read();a=read();b=read();x1=read();t=read();
        printf("%lld\n",solve());
    }
    return 0;
}