#include <bits/stdc++.h>
using namespace std;
inline bool EQ(double a, double b) { return fabs(a - b) < 1e-9; }
template <typename T>
inline T gcd(T a, T b) {
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}
template <typename T>
inline T lcm(T a, T b) {
  return (a * b) / gcd(a, b);
}
template <typename T>
string toStr(T x) {
  stringstream st;
  st << x;
  string s;
  st >> s;
  return s;
}
template <class T>
void splitStr(const string &s, vector<T> &out) {
  istringstream in(s);
  out.clear();
  copy(istream_iterator<T>(in), istream_iterator<T>(), back_inserter(out));
}
inline int two(int n) { return 1 << n; }
inline int isOnBit(int n, int b) { return (n >> b) & 1; }
inline void onBit(int &n, int b) { n |= two(b); }
inline void offBit(int &n, int b) { n &= ~two(b); }
inline int lastBit(int n) { return n & (-n); }
inline int cntBit(int n) {
  int res = 0;
  while (n && ++res) n -= n & (-n);
  return res;
}
const int dx4[] = {-1, 0, 1, 0};
const int dy4[] = {0, 1, 0, -1};
const int dx8[] = {-1, 0, 1, 0, -1, -1, 1, 1};
const int dy8[] = {0, 1, 0, -1, -1, 1, -1, 1};
int n, m, a[102 + 5], t, l, r, x, v;
long long f[102 + 5], f2[102 + 5];
void gen() {
  f[0] = f[1] = 1;
  for (int i = (2), _b = (102); i <= _b; i++)
    f[i] = f[i - 1] + f[i - 2], f[i] %= 1000000000;
}
int main() {
  gen();
  scanf("%d%d", &n, &m);
  for (int i = (1), _b = (n); i <= _b; i++) scanf("%d", &a[i]);
  while (m--) {
    scanf("%d %d %d", &t, &x, &v);
    l = x;
    r = v;
    if (t == 1) {
      a[x] = v;
      a[x] %= 1000000000;
    } else if (t == 2) {
      long long ans = 0;
      for (int i = 0, _n = (r - l + 1); i < _n; i++) {
        ans += ((1ll * f[i] * a[l + i]) % 1000000000);
        ans %= 1000000000;
      }
      cout << ans << endl;
    }
  }
  return 0;
}
