#include <iostream>
using namespace std;
int main() {
int N, K, i, j, jangkauan;
cin >> N >> K;
int jpatok[N], jbebek[K], jarak[N];
int mid;
for (i = 0; i < N; i++) {
cin >> jpatok[i];
if (i == 0) {
jarak[i] = jpatok[i];
} else {
jarak[i] = jpatok[i] + jarak[i - 1];
}
}
for (j = 0; j < K; j++) {
cin >> jbebek[j];
}
cout<<jarak[1]<<endl;
return 0;
}
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