#include <bits/stdc++.h>
using namespace std;
int main() {
// your code goes here
vector<int> a;
vector<int> b;
int la,lb;
cin>>la>>lb;
for(int i=0;i<la;i++)
{
int num;
cin>>num;
a.push_back(num);
}
for(int i=0;i<lb;i++)
{
int num;
cin>>num;
b.push_back(num);
}
// Actual logic
int count = 0;
int pa=0,pb=0;
while(pa<la and pb<lb)
{
if(a[pa]>b[pb])
{
count+=(la-pa);
pb++;
}
else
{
pa++;
}
}
cout<<count;
return 0;
}
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