const int _bod_=10000;struct BN{    static const int N=1010;int a[N];    BN(){memset(a,0,sizeof(a));}    int& operator [](int n){return a[n];}    BN operator =(int n){         memset(a,0,sizeof(a));         a[1]=n;if(a[1])a[0]=1;         while(a[a[0]+1]){a[a[0]+1]=a[a[0]]/_bod_;a[a[0]++]%=_bod_;}         return *this;    }    bool operator <(BN b) const{        if(a[0]<b[0])return 1;        if(a[0]>b[0])return 0;        for(int i=a[0];i>=1;i--){            if(a[i]>b[i])return 0;            if(a[i]<b[i])return 1;        }        return 0;    }    BN operator +(BN b) const{        b[0]=max(a[0],b[0]);        for(int i=1;i<=b[0];i++){            b[i]+=a[i];            if(b[i]>=_bod_){b[i+1]+=b[i]/_bod_;b[i]%=_bod_;}        }        if(b[b[0]+1])b[0]++;        return b;    }    BN operator -(BN b) const{        BN ans=*this;int q=1;        if(ans<b)swap(ans,b),q=-1;        for(int i=1;i<=ans[0];i++){            ans[i]=ans[i]-b[i];            if(ans[i]<0){ans[i+1]--;ans[i]+=_bod_;}        }        while(ans[0]&&!ans[ans[0]])ans[0]--;        for(int i=1;i<=ans[0];i++)ans[i]*=q;        return ans;    }    BN operator *(BN b) const{        BN ans;        ans[0]=a[0]+b[0]-1;        for(int i=1;i<=a[0];i++)            for(int o=1;o<=b[0];o++){                int now=i+o-1;                ans[now]+=a[i]*b[o];            }        for(int i=1;i<=ans[0];i++)if(ans[i]>=_bod_){ans[i+1]+=ans[i]/_bod_;ans[i]%=_bod_;}        if(ans[ans[0]+1])ans[0]++;        return ans;    }    void operator +=(BN b){*this=*this+b;}    void operator -=(BN b){*this=*this-b;}    void operator *=(BN b){*this=*this*b;}    void print(){printf("%d",a[a[0]]);for(int i=a[0]-1;i>=1;i--)printf("%.4d",a[i]);}//.xd x=_bod_后导零的个数(位数)};