Max sum path in two arrays

/*
Given two sorted arrays A and B. The task is to complete the function max_path_sum that takes 4 argument, 
the first two arguments represent the 2 arrays A[] and B[] and the last two arguments l1, l2 denote 
the size of array A and B respectively. The function returns the sum of the maximum sum path to reach 
from beginning of any array to end of any of the two arrays .

Note: You can switch from one array to another array only at common elements.

*/

#include<bits/stdc++.h>
using namespace std;
int max_path_sum(int [], int [], int , int );
int main()
{
    int N,M;
    cin>>N>>M;
    fflush(stdin);
    int a[N],b[M];
    for(int i=0;i<N;i++)
        cin>>a[i];
    for(int i=0;i<M;i++)
        cin>>b[i];
    int result = max_path_sum(a,b,N,M);
    cout<<result<<endl;
        
    return 0;
}

int max_path_sum(int A[], int B[], int l1, int l2)
{
    //Your code here
    int sum = 0;
    int sum2 = 0;
    int i = 0;
    int j = 0; 
    while(i < l1 && j < l2) {
        if(A[i] == B[j]) {
            sum = max(sum , sum2) + A[i];
            sum2 = sum;
            i++;
            j++;
        } else {
            if(A[i] > B[j]) {
                sum2 = sum2 + B[j];
                j++;
            } else {
                sum = sum + A[i];
                i++;
            }
        }       
    }  
       
    while(i < l1) {
        sum = sum + A[i];
        i++;
    }
    while(j < l2) {
        sum2 = sum2 + B[j];
        j++;
    }
    
    return max(sum, sum2);
}

/*
INPUT:
5 4
2 3 7 10 12
1 5 7 8 

OUTPUT:
35
*/