Convolution giving wrong answer

Below is the link to question:

Here is my solution ,I dont know in which case its failing:

#include<iostream>
#include<cstdio>
#define FAST_IO ios_base::sync_with_stdio(false);cin.tie(NULL);

using namespace std;

int main()
{
FAST_IO
int T,N,M,Q;
cin>>T;
while(T--)
{
	cin>>N>>M;
	long long int A[N],B[M],sum_A=0,sum_B=0	, n,L,R,X;;
	for(int i=0;i<N;i++)
	{
		cin>>A[i];
		sum_A=sum_A+A[i];
	}
	
	for(int i=0;i<M;i++)
	{
		cin>>B[i];
		sum_B=sum_B+B[i];
	}

	cin>>Q;
	while(Q--)
	{
	
		cin>>n;
        
		if(n==1)
		{
	    	cin>>L>>R>>X;
			sum_A=sum_A+((R-L+1)*X);
			
		}
		else if(n==2)
		{
			cin>>L>>R>>X;	
			sum_B=sum_B+((R-L+1)*X);
		}
		else 
		{
		long long int sum=0;
				sum=((sum_A%998244353)*(sum_B%998244353))%998244353;
			cout<<sum<<"\n";
		}
	
	

	
	}



}
return 0;
}

In queries of type 1 and 2, when you add values to sum_a or sum_b, do it using the modular addition

I have modified the code but still getting wrong answer:

#include<iostream>
#include<cstdio>
#define FAST_IO ios_base::sync_with_stdio(false);cin.tie(NULL);

using namespace std;

int main()
{
FAST_IO
int T,N,M,Q;
cin>>T;
while(T--)
{
	cin>>N>>M;
	long long int A[N],B[M],sum_A=0,sum_B=0	, n,L,R,X;;
	for(int i=0;i<N;i++)
	{
		cin>>A[i];
		sum_A=((sum_A%998244353)+(A[i]%998244353))%998244353;
	}
	
	for(int i=0;i<M;i++)
	{
		cin>>B[i];
		sum_B=((sum_B%998244353)+(B[i]%998244353))%998244353;
	}

	cin>>Q;
	while(Q--)
	{
	
		cin>>n;
        
		if(n==1)
		{
	    	cin>>L>>R>>X;
			sum_A=((sum_A%998244353)+(((R-L+1)*X)%998244353))%998244353;
			
		}
		else if(n==2)
		{
			cin>>L>>R>>X;	
			sum_B=((sum_B%998244353)+(((R-L+1)*X)%998244353))%998244353;
		}
		else 
		{
		long long int sum=0;
				sum=((sum_A%998244353)*(sum_B%998244353))%998244353;
			cout<<sum<<"\n";
		}
	
	

	
	}



}
return 0;
}

you are not doing the modular addition correctly, numbers can be negative. Check this https://www.codechef.com/viewsolution/29264896