#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <iostream>
#include <sstream>
#include <vector>
#include <string>
#include <queue>
#include <list>
#include <algorithm>
#include <map>
#include <set>
#include <stack>
using namespace std;

#define ALL(c) (c).begin(),(c).end()
#define IN(x,c) (find(c.begin(),c.end(),x) != (c).end())
#define REP(i,n) for (int i=0;i<(int)(n);i++)
#define FOR(i,a,b) for (int i=(a);i<=(b);i++)
#define INIT(a,v) memset(a,v,sizeof(a))
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
template<class A, class B> A cvt(B x) { stringstream ss; ss<<x; A y; ss>>y; return y; }

typedef pair<int,int> PII;
typedef vector<int> VI;
typedef long long int64;

int main() {
	int n,m;
	scanf("%d %d",&n,&m);
	vector<VI> g,t;
	int a,b;
	REP (i,n) {
		scanf("%d",&a);
		g.push_back({a,i});
	}
	sort(ALL(g));
	REP (i,m) {
		scanf("%d %d",&a,&b);
		t.push_back({a,b,i});
	}
	sort(ALL(t));
	priority_queue<VI,vector<VI>,greater<VI> > pq;
	vector<VI> sol;
	int j=0;
	REP (i,n) {
		while (j<m && t[j][0]<=g[i][0]) {
			pq.push({t[j][1], t[j][2]});
			j++;
		}
		while (!pq.empty() && pq.top()[0]<g[i][0]) {
			pq.pop();
		}
		if (!pq.empty()) {
			VI ti = pq.top();
			pq.pop();
			sol.push_back({g[i][1],ti[1]});
		}
	}
	printf("%d\n",(int)sol.size());
	for (VI s : sol) {
		printf("%d %d\n",s[0]+1,s[1]+1);
	}
	return 0;
}