#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")


constexpr Int INF = 1001001001001001001LL;

int N, Q;
vector<Int> A, B;
vector<int> O, P, L, R, K;
vector<Int> X, Y;

vector<Int> brute() {
  auto as = A, bs = B;
  vector<Int> ans(Q, 0);
  for (int q = 0; q < Q; ++q) {
    if (O[q] == 1) {
      as[P[q]] = X[q];
      bs[P[q]] = Y[q];
    } else {
      vector<Int> dp(2 * (R[q] - L[q]) + 1, INF);
      dp[0] = 0;
      for (int i = L[q]; i < R[q]; ++i) {
        for (int k = 2 * (i - L[q]); k >= 0; --k) {
          chmin(dp[k + 1], dp[k] + as[i]);
          chmin(dp[k + 2], dp[k] + bs[i]);
        }
      }
      ans[q] = dp[K[q]];
    }
  }
  return ans;
}

int main() {
  for (; ~scanf("%d%d", &N, &Q); ) {
    A.resize(N);
    B.resize(N);
    for (int i = 0; i < N; ++i) {
      scanf("%lld%lld", &A[i], &B[i]);
      assert(0 < A[i]); assert(A[i] < B[i]);
    }
    O.assign(Q, -1);
    P.assign(Q, -1);
    L.assign(Q, -1);
    R.assign(Q, -1);
    K.assign(Q, -1);
    X.assign(Q, -1);
    Y.assign(Q, -1);
    for (int q = 0; q < Q; ++q) {
      scanf("%d", &O[q]);
      if (O[q] == 1) {
        scanf("%d%lld%lld", &P[q], &X[q], &Y[q]);
        assert(0 <= P[q]); assert(P[q] < N);
        assert(0 < X[q]); assert(X[q] < Y[q]);
      } else if (O[q] == 2) {
        scanf("%d%d%d", &L[q], &R[q], &K[q]);
        ++R[q];
        assert(0 <= L[q]); assert(L[q] < R[q]); assert(R[q] <= N);
      } else {
        assert(false);
      }
    }
    
    const auto ans = brute();
    for (int q = 0; q < Q; ++q) if (O[q] == 2) {
      printf("%lld\n", ans[q]);
    }
  }
  return 0;
}