#include<bits/stdc++.h>
#define re register
using namespace std;
inline int read(){
	re int t=0;re char v=getchar();
	while(v<'0')v=getchar();
	while(v>='0')t=(t<<3)+(t<<1)+v-48,v=getchar();
	return t;
}
const int M=998244353;
inline void add(re int &x,re int y){(x+=y)>=M?x-=M:x;}
inline int Mod(re int x){return x>=M?x-M:x;}
inline int ksm(re int x,re int y){
	re int s=1;
	while(y){
		if(y&1)s=1ll*s*x%M;
		x=1ll*x*x%M,y>>=1;
	}
	return s;
}
int t,n,m,a[1000002],ans,R[1000002],stk[1000002],tp,lst;
char s[1000002];
vector<int>A,B;
int main(){
	n=read(),m=read();
	if(n>m)swap(n,m),ans=1;
	lst=0;
	int oo=0;
	for(re int i=1;i+n<=m;i+=n){
		lst=i;
		for(re int j=1;j<=n;++j)A.push_back(j),B.push_back(i);
	}
	oo=lst;
	for(re int j=1;j<=n;++j)A.push_back(j),B.push_back(m);
	if(lst)lst=lst+m+1>>1;
	else lst=1;
	re int dlt=m-lst;
	if(dlt){
		for(re int i=1;i<=n;++i){
			if(i>dlt)s[i-dlt]=1;
			if(i+dlt<=n)s[i+dlt]=1;
		}
		for(re int i=1;i<=n;++i)if(!s[i]){
			A.push_back(i),B.push_back(lst);
			if(lst-oo!=m-lst&&n!=m)A.push_back(i),B.push_back(lst-1),++i;
		}
	}
	printf("%u\n",A.size());
	for(re int i=0;i<A.size();++i){
		if(ans)swap(A[i],B[i]);
		printf("%d %d\n",A[i],B[i]);
	} 
}