#include<vector>
#include<iostream>

using namespace std;

struct cluster {
    int id, pos;
    cluster(int id, int pos) {
        this->id = id;
        this->pos = pos;
    }
    cluster() {}
};

bool operator != (cluster a, cluster b) {
    return a.id!=b.id or a.pos!=b.pos;
}

int n;
typedef pair<int,int> pii;
vector<vector<int> > file;
vector<cluster> disk;
vector<pii> ans;

int firstempty;

void find1stempty(int ini=0) {
    for(firstempty=ini; disk[firstempty]!=cluster(-1,-1); firstempty++);
//    cout<<"#"<<firstempty<<"\n";
}

void moveone(int x,int y) {
    ans.push_back(pii(x,y));
//    cout<<"$"<<x<<" "<<y<<"\n";
    cluster ant = disk[x];
    disk[y] = ant;
    disk[x] = cluster(-1,-1);
    file[ant.id][ant.pos] = y;
}

void desp(int x,int y) {
    if(firstempty>x) {
        moveone(x,firstempty);
        swap(firstempty,x);
    }
    for(int i=firstempty-1; i>=y; i--) {
        moveone(i,i+1);
        firstempty = i;
    }
    moveone(x,firstempty);
    find1stempty(y+1);
}

void desp2(int x,int y) {
    moveone(x,firstempty);
    swap(firstempty,x);
    for(int i=firstempty+1; i<=y; i++) {
        moveone(i,i-1);
        firstempty = i;
    }
    moveone(x,y);
    find1stempty(y+1);
}

int main() {
    int m;
    cin >> n >> m;
    file.resize(m);
    disk.assign(n,cluster(-1,-1));
    for(int i=0,tam; i<m; i++) {
        cin >> tam;
        file[i].resize(tam);
        for(int j=0; j<tam; j++) {
            cin >> file[i][j];
            file[i][j] --;
            disk[file[i][j]] = cluster(i,j);
        }
    }
    find1stempty();

    for(int i=0,tam; i<m; i++) {
        if(firstempty<file[i][0]) {
            moveone(file[i][0],firstempty);
            find1stempty(file[i][0]+1);
        }
        tam = file[i].size();
        for(int j=1; j<tam; j++) {
            int x = file[i][j];
            int y = file[i][j-1];
            if(x>y+1)
                desp(x,y+1);
            else if(x<y+1)
                desp2(x,y);
        }
    }
    cout<<ans.size()<<endl;
    for(auto x:ans) {
        cout << x.first+1 << " " << x.second+1 << "\n";
    }
}