A. T4k3D4Ch14

#include <iostream>
#include <vector>
using namespace std;

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(NULL); cout.tie(NULL);

    int n, m, ans = 0; cin >> n >> m;
    vector<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 ptr1 = 0, ptr2 = 0, s1 = a[0], s2 = b[0];
    while (ptr1 < n && ptr2 < m) {
        if (s1 == s2) {
            ptr1++; ptr2++; ans++;
            s1 += a[ptr1]; s2 += b[ptr2];
        }
        else if (s1 < s2) {ptr1++; s1 += a[ptr1];}
        else {ptr2++; s2 += b[ptr2];}
    }

    cout << ans;
    return 0;
}