WA on #5,#6,#7,#10

#include<bits/stdc++.h>
using namespace std;
#define un unsigned
#define ll long long
//#define int long long
//#define int __int128
#define in inline
//#define re register
#define isdigit isisisdigit
in void dswap(int &x,int &y){
	int z=x;
	x=y,y=z;
}
in void cswap(char &x,char &y){
	char z=x;
	x=y,y=z;
}
in void fswap(double &x,double &y){
	double z=x;
	x=y,y=z;
}
in bool isdigit(char x){
	return x>=48&&x<=57;
}
#define gc() getchar()
#define pc(x) putchar(x)
in int read(){
	int x=0,f=1;
	char ch=gc();
	while(!isdigit(ch)){
		if(ch=='-')f=-1;
		ch=gc();
	}
	while(isdigit(ch))
		x=(x<<3)+(x<<1)+(ch^48),
		ch=gc();
	return f*x;
}
void print(int x,char ch=0){
	if(x<0)pc('-'),x=-x;
	if(x>9)print(x/10);
	pc(x-x/10*10+48);
	if(ch)pc(ch);
}
#define abs(x) (x<0?-x:x)
#define max(x,y) (x>y?x:y)
#define min(x,y) (x<y?x:y)
const int N=1005;
int inf=1e9,mod=998244353;
int n,m,a[N],b[N],cnt,sa,sb,flag,ans;
signed main(){
	n=read(),m=read();
	for(int i=1;i<=n;i++){
		int v=read(),t=read();
		while(t--)a[++cnt]=v;
	}
	cnt=0;
	for(int i=1;i<=m;i++){
		int v=read(),t=read();
		while(t--)b[++cnt]=v;
	}
	for(int i=1;i<=cnt;i++){
		sa+=a[i],sb+=b[i];
		if(sa>sb&&flag==1)ans++;
		if(sa<sb&&flag==2)ans++;
		if(sa>sb)flag=2;
		if(sa<sb)flag=1;
		//puts("");
		//print(sa,' '),print(sb,' '),print(flag,' ');
	}
	print(ans,'\n');
	return 0;
}