#include <bits/stdc++.h> using namespace std; int N; int M; int l[500100]; int g[500100]; long long int mod = 1'000'000'007; int nxt[2][500100]; int v[2][500100][30]; vector<int> va; void update(int i, int num, bool flag){ int it = nxt[flag][i - 1]; while(it <= num && it != -1){ if(!flag){ for(int i = 1; i <= 26; i++){ va[i] = (va[i] - v[flag][it][i - 1] + mod) % mod; } } else{ for(int i = 1; i <= 26; i++){ va[i] = (va[i] - v[flag][it][i + 1] + mod) % mod; } } it = nxt[flag][it]; } nxt[flag][i - 1] = it; } int main(){ //while(true){ scanf(" %d",&N); scanf(" %d",&M); for(int i = 0; i < N; i++){ l[i] = i - 1; g[i] = i - 1; } for(int i = 1; i < N; i++){ nxt[0][i] = i + 1; nxt[1][i] = i + 1; } nxt[0][N] = -1; nxt[1][N] = -1; for(int i = 0; i < M; i++){ int u, v; scanf(" %d",&u); scanf(" %d",&v); if(u > v){ l[v] = max(l[v],u); } else{ g[u] = max(g[u],v); } } v[0][N][0] = 0; v[1][N][27] = 0; for(int i = 1; i <= 26; i++){ v[0][N][i] = i; v[1][N][i] = 26 - i + 1; } for(int i = 0; i <= 26; i++) va.push_back(26); va[0] = 0; for(int i = N - 1; i >= 1; i--){ update(i + 1,g[i],0); update(i + 1,l[i],1); if(i == 1) break; v[0][i][0] = 0; v[0][i][27] = 0; for(int k = 1; k <= 26; k++){ v[0][i][k] = (v[0][i][k - 1] + va[k]) % mod; } v[1][i][0] = 0; v[1][i][27] = 0; for(int k = 26; k >= 1; k--){ v[1][i][k] = (v[1][i][k + 1] + va[k]) % mod; } for(int k = 1; k <= 26; k++){ va[k] = (v[0][i][k - 1] + va[k]) % mod; va[k] = (v[1][i][k + 1] + va[k]) % mod; } } long long int ans = 0; for(int i : va){ ans += i; } //printf("\n"); printf("%lld\n",ans % mod); //} } /* 10 8 2 10 2 10 3 10 4 10 5 10 6 10 7 10 8 10 */

misspelling.cpp: In function 'int main()':
misspelling.cpp:35:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |         scanf(" %d",&N);
      |         ~~~~~^~~~~~~~~~
misspelling.cpp:36:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         scanf(" %d",&M);
      |         ~~~~~^~~~~~~~~~
misspelling.cpp:53:22: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   53 |                 scanf(" %d",&u);
      |                 ~~~~~^~~~~~~~~~
misspelling.cpp:54:22: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   54 |                 scanf(" %d",&v);
      |                 ~~~~~^~~~~~~~~~