#include<bits/stdc++.h> // #include <ext/pb_ds/assoc_container.hpp> // #include <ext/pb_ds/tree_policy.hpp> using namespace std; // #define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update> // using namespace __gnu_pbds; typedef long long ll; #define int long long #define vi vector<int> #define vvi vector<vi> #define vll vector<ll> #define vvll vector<vll> #define pi pair<int,int> #define pll pair<ll,ll> #define ff first #define ss second #define vpi vector<pair<int,int>> #define rep(ii,st, n) for(int ii=st; ii<n; ii++) #define gp " " //bit_manupulation #define checkbit(x,n) (x&(1LL<<n)) #define setbit(x,n) (x=(x|(1LL<<n))) #define resetbit(x,n) (x=(x&(~(1LL<<n)))) #define pow2(i) (1LL<<i) #define bitcnt(x) ((sizeof(x) <= sizeof(int)) ? (32 - __builtin_clz(x)) : (64 - __builtin_clzll(x))) #define DEBG #define debug(n) #define debugc(a) #define debugcc(a) #ifdef DEBG #define debug(n) cout<<__LINE__<<gp<<#n<<gp<<n<<endl; #define debugc(a) cout<<__LINE__<<gp<<#a<<gp<<'['<<gp;for(auto el:a){cout<<el<<gp;}cout<<']'<<endl; #define debugcc(a) cout<<__LINE__<<gp<<#a<<gp<<'['<<gp;for(auto el:a){cout<<'{'<<gp<<el.ff<<','<<el.ss<<gp<<'}'<<gp;}cout<<']'<<endl; #endif #define fastcin() ios_base::sync_with_stdio(false); cin.tie(NULL); #define endl '\n' #define All(a) a.begin(),a.end() template<typename T> void get_vector(T&a){for(auto&e:a)cin>>e;} template<typename T> void put_vector(T a){for(auto e:a)cout<<e<<" ";cout<<endl;} const ll INF = 2e18; const ll inf = INT_MAX; const ll M = 1e9 + 7; const ll N = 2e5 + 7; const ll modinvof2 = 500000004; //==============================CODE STARTS HERE==============================// void preprocessing(){ } void solve(int testcases){ int n,m; cin>>n>>m; vi b(m),p(m); for(int i = 0; i<m; i++){ cin>>b[i]>>p[i]; } int ans = 1e16; int mx = 0; bool fl = false; for(int i = b[0]; i<n; i+=p[0]){ if(i == b[1]){ ans = min(ans,mx); } if(i == b[2]){ int smx = 0; for(int j = b[2]; j<n; j+=p[2]){ if(j == b[1]){ ans = min(ans,mx+smx); break; } smx++; } smx = 0; for(int j = b[2]; j>=0; j-=p[2]){ if(j == b[1]){ ans = min(ans,mx+smx); break; } smx++; } } mx++; } mx = 0; for(int i = b[0]; i>=0; i-=p[0]){ if(i == b[1]){ ans = min(ans,mx); } if(i == b[2]){ int smx = 0; for(int j = b[2]; j<n; j+=p[2]){ if(j == b[1]){ ans = min(ans,mx+smx); break; } smx++; } smx = 0; for(int j = b[2]; j>=0; j-=p[2]){ if(j == b[1]){ ans = min(ans,mx+smx); break; } smx++; } } mx++; } if(ans >= 1e12){ cout<<-1<<endl; return; } cout<<ans<<endl; } int32_t main(){ fastcin(); int t=1; // cin>>t; preprocessing(); rep(i,1,t+1){ solve(i); } return 0; }

skyscraper.cpp:37: warning: "debug" redefined
   37 | #define debug(n) cout<<__LINE__<<gp<<#n<<gp<<n<<endl;
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skyscraper.cpp:33: note: this is the location of the previous definition
   33 | #define debug(n)
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skyscraper.cpp:38: warning: "debugc" redefined
   38 | #define debugc(a) cout<<__LINE__<<gp<<#a<<gp<<'['<<gp;for(auto el:a){cout<<el<<gp;}cout<<']'<<endl;
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skyscraper.cpp:34: note: this is the location of the previous definition
   34 | #define debugc(a)
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skyscraper.cpp:39: warning: "debugcc" redefined
   39 | #define debugcc(a) cout<<__LINE__<<gp<<#a<<gp<<'['<<gp;for(auto el:a){cout<<'{'<<gp<<el.ff<<','<<el.ss<<gp<<'}'<<gp;}cout<<']'<<endl;
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skyscraper.cpp:35: note: this is the location of the previous definition
   35 | #define debugcc(a)
      |