#include <iostream>
#include <algorithm>

using namespace std;

struct rendeles {
    int sor, hat;
};

bool rule(rendeles x, rendeles y) {
    return x.hat<y.hat;
}

int main() {
    int n, m, k;
    cin >> n >> m >> k;
    rendeles a[10001];
    for(int i=1; i<=m; i++) {
        cin >> a[i].hat;
        a[i].sor=i;
    }
    sort(a+1, a+m+1, rule);
    
    for(int i=1; i<=m; i++) {
        cout << a[i].sor << ", " << a[i].hat << endl;
    }
    
    cout << endl;

    rendeles b[10001];

    //lets change this while to check each day

    int lim, q=1, x=1;
    for(int i=1; i<=n; i++) {
        lim=0;
        while(lim<k && q<=m) {
            if(a[q].hat>=i) {
                b[x].sor=a[q].sor;
                b[x].hat=i;
                lim++;
                x++;
                q++;
            }
        }
        while(a[q].hat==i) q++;
    }
    
    cout << x-1 << endl;
    
    for(int i=1; i<x; i++) {
        cout << b[i].sor << " " << b[i].hat << endl;
    }
    return 0;
}