Codechef：Fibonacci Number/FN——求通项+二次剩余+bsgs

//minamoto
#include<bits/stdc++.h>
#define R register
#define inf 0x7fffffff
#define fp(i,a,b) for(R int i=(a),I=(b)+1;i<I;++i)
#define fd(i,a,b) for(R int i=(a),I=(b)-1;i>I;--i)
#define go(u) for(int i=head[u],v=e[i].v;i;i=e[i].nx,v=e[i].v)
template<class T>inline bool cmin(T&a,const T&b){return a>b?a=b,1:0;}
using namespace std;
char buf[1<<21],*p1=buf,*p2=buf;
inline char getc(){return p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++;}
int read(){
    R int res,f=1;R char ch;
    while((ch=getc())>‘9‘||ch<‘0‘)(ch==‘-‘)&&(f=-1);
    for(res=ch-‘0‘;(ch=getc())>=‘0‘&&ch<=‘9‘;res=res*10+ch-‘0‘);
    return res*f;
}
char sr[1<<21],z[20];int C=-1,Z=0;
inline void Ot(){fwrite(sr,1,C+1,stdout),C=-1;}
void print(R int x){
    if(C>1<<20)Ot();if(x<0)sr[++C]=‘-‘,x=-x;
    while(z[++Z]=x%10+48,x/=10);
    while(sr[++C]=z[Z],--Z);sr[++C]=‘\n‘;
}
int P;
inline int add(R int x,R int y){return 0ll+x+y>=P?0ll+x+y-P:x+y;}
inline int dec(R int x,R int y){return x-y<0?x-y+P:x-y;}
inline int mul(R int x,R int y){return 1ll*x*y-1ll*x*y/P*P;}
int ksm(R int x,R int y){
    R int res=1;
    for(;y;y>>=1,x=mul(x,x))(y&1)?res=mul(res,x):0;
    return res;
}
int w,a;
struct cp{
    int x,y;
    inline cp(R int _x,R int _y):x(_x),y(_y){}
    inline cp operator *(const cp &b)const{
        return cp(add(mul(x,b.x),mul(w,mul(y,b.y))),add(mul(x,b.y),mul(y,b.x)));
    }
};
int ksm(R cp x,R int y){
    R cp res(1,0);
    for(;y;y>>=1,x=x*x)if(y&1)res=res*x;
    return res.x;
}
int Sqrt(int x){
    if(!x)return 0;
    if(ksm(x,(P-1)>>1)==P-1)return -1;
    while(true){
        a=mul(rand(),rand()),w=dec(mul(a,a),x);
        if(ksm(w,(P-1)>>1)==P-1)return ksm(cp(a,1),(P+1)>>1);
    }
}
const int N=262144;
struct Hash{
    struct eg{int v,nx,w;}e[N];int head[N],tot;
    inline void clr(){memset(head,0,sizeof(head)),tot=0;}
    inline void add(R int v,R int w){e[++tot]={v,head[v&262143],w},head[v&262143]=tot;}
    int query(int x){
        go(x&262143)if(v==x)return e[i].w;
        return -1;
    }
}mp[2];
int bsgs(int x,int v,int sgn){
    int m=sqrt(P)+1;mp[0].clr(),mp[1].clr();
    for(R int i=1,res=mul(v,x);i<=m;++i,res=mul(res,x))mp[i&1].add(res,i);
    for(R int i=1,tmp=ksm(x,m),res=tmp;i<=m;++i,res=mul(res,tmp))
        if(mp[(i*m)&1^sgn].query(res)!=-1)return i*m-mp[(i*m)&1^sgn].query(res);
    return inf;
}
int c,s,p,inv2,res,rt;
int main(){
    srand(time(NULL));
//  freopen("testdata.in","r",stdin);
    for(int T=read();T;--T){
        c=read(),P=read(),s=Sqrt(5),inv2=(P+1)>>1,p=mul(s+1,inv2),c=mul(c,s);
        res=inf;
        rt=Sqrt((1ll*c*c+4)%P);
        if(rt!=-1){
            cmin(res,bsgs(p,mul(add(c,rt),inv2),0)),
            cmin(res,bsgs(p,mul(dec(c,rt),inv2),0));
        }
        rt=Sqrt((1ll*c*c+P-4)%P);
        if(rt!=-1){
            cmin(res,bsgs(p,mul(add(c,rt),inv2),1)),
            cmin(res,bsgs(p,mul(dec(c,rt),inv2),1));
        }
        printf("%d\n",res==inf?-1:res);
    }
    return 0;
}