// library begin: "lib/template.hpp"
#ifdef TEMPLATE
#else
#define TEMPLATE
# pragma GCC optimize("O3")
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <string>
#include <cstring>
#include <vector>
#include <list>
#include <queue>
#include <stack>
#include <deque>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <algorithm>
#include <numeric>
#include <cmath>
#include <climits>
#include <cassert>
#include <functional>
#include <iterator>
#include <utility>
#include <complex>
#include <bitset>
#include <chrono>
#include <random>
#include <limits>
#include <optional>
#include <variant>
#include <any>

#include <array>
#include <bit>
#include <compare>
#include <concepts>
#include <numbers>
#include <ranges>
#include <span>
#include <string_view>
#include <tuple>
#include <type_traits>
#include <version>
using namespace std;
namespace ryoku{}
using uint=unsigned;
using ll=long long;
using ull=unsigned long long;
using ld=long double;
using pii=pair<int,int>;
using pll=pair<ll,ll>;
using i128=__int128;
using u128=unsigned __int128;
template<class T>using vc=vector<T>;
template<class T>using vvc=vc<vc<T>>;
template<class T>using vvvc=vvc<vc<T>>;
template<class T>using smpq=priority_queue<T,vector<T>,greater<T>>;
template<class T>using bipq=priority_queue<T>;
#define rep(i,n) for(ll i=0;i<(ll)(n);i++)
#define REP(i,j,n) for(ll i=(j);i<(ll)(n);i++)
#define DREP(i,n,m) for(ll i=(n);i>=(m);i--)
#define drep(i,n) for(ll i=((n)-1);i>=0;i--)
#define rall(x) x.rbegin(),x.rend()
#define mp(...) make_pair(__VA_ARGS__)
#define pb push_back
#define fi first
#define se second
#define is insert
#define bg begin()
#define ed end()
#define all(x) x.begin(),x.end()
void scan(int&a) { cin >> a; }
void scan(ll&a) { cin >> a; }
void scan(string&a) { cin >> a; }
void scan(char&a) { cin >> a; }
void scan(uint&a) { cin >> a; }
void scan(ull&a) { cin >> a; }
void scan(bool&a) { cin >> a; }
void scan(ld&a){ cin>> a;}
template<class T> void scan(vector<T>&a) { for(auto&x:a) scan(x); }
void read() {}
template<class Head, class... Tail> void read(Head&head, Tail&... tail) { scan(head); read(tail...); }
#define INT(...) int __VA_ARGS__; read(__VA_ARGS__);
#define LL(...) ll __VA_ARGS__; read(__VA_ARGS__);
#define ULL(...) ull __VA_ARGS__; read(__VA_ARGS__);
#define STR(...) string __VA_ARGS__; read(__VA_ARGS__);
#define VC(type, name, ...) vector<type> name(__VA_ARGS__); read(name);
#define VVC(type, name, size, ...) vector<vector<type>> name(size, vector<type>(__VA_ARGS__)); read(name);
template<class T>void print(T a) { cout << a; }
template<class T> void print(vector<T>a) { for(int i=0;i<(int)a.size();i++){if(i)cout<<" ";print(a[i]);}}
void PRT() { cout <<endl; return ; }
template<class T> void PRT(T a) { print(a); cout <<endl; return; }
template<class Head, class... Tail> void PRT(Head head, Tail ... tail) { print(head); cout << " "; PRT(tail...); return; }
template<class T,class F>
bool chmin(T &x, F y){
    if(x>y){
        x=y;
        return true;
    }
    return false;
}
template<class T, class F>
bool chmax(T &x, F y){
    if(x<y){
        x=y;
        return true;
    }
    return false;
}
template<typename T>
T floor(T a,T b){
    return a/b-(a%b&&((a<0)!=(b<0)));
}
template<typename T>
T ceil(T a,T b){
    return a/b+(a%b&&((a<0)==(b<0)));
}
template<typename T>
T bmod(T x,T y){
    return x-y*floor(x,y);
}
template<typename T>
pair<T,T>divmod(T x,T y){
    T q=floor(x,y);
    return{q,x-q*y};
}
void YesNo(bool b){
    cout<<(b?"Yes":"No")<<endl;
}
void YESNO(bool b){
    cout<<(b?"YES":"NO")<<endl;
}
void AliceBob(bool b){
    cout<<(b?"Alice":"Bob")<<endl;
}
void TakahashiAoki(bool b){
    cout<<(b?"Takahashi":"Aoki")<<endl;
}
void Yes(){
    cout<<"Yes"<<endl;
}
void No(){
    cout<<"No"<<endl;
}
vc<int>stovi(const string&s,const string&S){
    vc<int>v(s.size());
    rep(i,s.size()){
        auto t=S.find(s[i]);
        assert(t!=string::npos);
        v[i]=t;
    }
    return v;
}
template<class T=ll>
T isqrt(T x){
    T F=sqrtl(x);
    while((F+1)*(F+1)<=x)F++;
    while(F*F>x)F--;
    return F;
}
template<class T>
T tri(T x){return x*(x-1)/2;}

//[l,r)
template<class T>T tri(T l,T r){return (r-l)*(l+r-1)/2;}
//n を先頭に持ってくる
template<class T>
vc<T>rot(vc<T>v,int n){
    rotate(v.begin(),v.begin()+n,v.end());
    return v;
}
template<class Container>
auto rle(const Container&cv){
    using T=typename Container::value_type;
    vc<pair<T,int>>res;
    for(const auto&x:cv){
        if(res.empty()||res.back().fi!=x)res.pb({x,1});
        else res.back().se++;
    }
    return res;
}
template<class T>
vc<T>iota(int n){
    vc<T>v(n);rep(i,n)v[i]=i;
    return v;
}
template<class T,int minfirst>
vc<int>argsort(const vc<T>&a){
    auto idx=iota<int>(a.size());
    sort(all(idx),[&](int i,int j){
        return (minfirst?make_pair(a[i],i)<make_pair(a[j],j):make_pair(a[i],i)>make_pair(a[j],j));
    });
    return idx;
}
template<class T>
vvc<T>trans(const vvc<T>&a){
    assert(a.size()&&a[0].size());
    rep(i,a.size())assert(a[i].size()==a[0].size());
    vvc<T>b(a[0].size(),vc<T>(a.size()));
    rep(i,a.size())rep(j,a[0].size())b[j][i]=a[i][j];
    return b;
}
vc<string>trans(const vc<string>&a){
    assert(a.size()&&a[0].size());
    rep(i,a.size())assert(a[i].size()==a[0].size());
    vc<string>b(a[0].size(),string(a.size(),0));
    rep(i,a.size())rep(j,a[0].size())b[j][i]=a[i][j];
    return b;
}
template<class T>
int popcount(T n){
    return __builtin_popcountll(n);
}
template<class T,class L=ll>
L sum(const vc<T>&a){
    return accumulate(all(a),L(0));
}
template<class T>
struct subset_view{
    T s;
    struct iterator{
        T s,x;
        bool done;
        T operator*()const{return x;}
        iterator&operator++(){
            if(x==0)done=true;
            else x=(x-1)&s;
            return*this;
        }
        bool operator!=(const iterator&r)const{return done!=r.done;}
    };
    iterator begin()const{return{s,s,false};}
    iterator end()const{return{s,0,true};}
};
template<class T>
subset_view<T>subset(T s){
    return{s};
}
template<class T>
T max(vc<T>&a){
    return *max_element(all(a));
}
template<class T>
T min(vc<T>&a){
    return *min_element(all(a));
}
template<class T,class L=ll>
vc<L> presum(vc<T> &a){
    vc<L> ret(a.size()+1);
    rep(i,a.size())ret[i+1]=ret[i]+a[i];
    return ret;
}
template<class T, class F>
vc<T> &operator+=(vc<T> &a,F b){
    for (auto&v:a)v += b;
    return a;
}
template<class T, class F>
vc<T> &operator-=(vc<T>&a,F b){
    for (auto&v:a)v-=b;
    return a;
}
template<class T, class F>
vc<T> &operator*=(vc<T>&a,F b){
    for (auto&v:a)v*=b;
    return a;
}
template<class T=ll>
constexpr T pow(T a,T b){
    T res=1;
    while(b){
        if(b&1)res*=a;
        a*=a;
        b/=2;
    }
    return res;
}
constexpr ll ten(ll a){
    return pow<ll>(10,a);
}
template<typename T>constexpr T inf=numeric_limits<T>::max()/2-1;
template<>
constexpr pll inf<pll> ={inf<ll>,inf<ll>};
template<class T>
constexpr T neg_inf=-inf<T>;
template<>
constexpr pll neg_inf<pll> ={-inf<ll>,-inf<ll>};
template<class T>
int tbit(T x){
    using U=make_unsigned_t<T>;
    U y=(U)x;
    return y?(int)bit_width(y)-1:-1;
}
template<class T>
int lbit(T x){
    using U=make_unsigned_t<T>;
    U y=(U)x;
    return y?(int)countr_zero(y):-1;
}
template<class T>
int tbit(T x,int p){
    using U=make_unsigned_t<T>;
    constexpr int W=numeric_limits<U>::digits;
    U y=(U)x;
    if(p<0)return -1;
    if(p>=W-1)return tbit(y);
    return tbit(y&((U(1)<<(p+1))-1));
}
template<class T>
int lbit(T x,int p){
    using U=make_unsigned_t<T>;
    constexpr int W=numeric_limits<U>::digits;
    U y=(U)x;
    if(p<0)return lbit(y);
    if(p>=W)return -1;
    return lbit(y&(~U(0)<<p));
}
istream& operator>>(istream&is,i128&x){
    string s;is>>s;
    x=0;
    int i=0,neg=0;
    if(s[0]=='-')neg=1,i=1;
    for(;i<(int)s.size();i++)x=x*10+s[i]-'0';
    if(neg)x=-x;
    return is;
}
ostream& operator<<(ostream&os,i128 x){
    if(x==0)return os<<0;
    if(x<0)os<<"-";
    u128 y=x<0?-(u128)x:(u128)x;
    string s;
    while(y)s.pb('0'+y%10),y/=10;
    reverse(all(s));
    return os<<s;
}
#ifdef LOCAL
#include"lib/debug/local.hpp"
inline int dbging=1;
#else
#define dbg(...) ((void)0)
#endif

struct template_setup{
    template_setup(){
        #ifdef LOCAL
        freopen("input.txt","r",stdin);
        freopen("output.txt","w",stdout);
        
        #endif
        cin.tie(0)->sync_with_stdio(0);
        #ifdef LOCAL
        cout<<fixed<<setprecision(6);
        #else
        cout<<fixed<<setprecision(20);
        #endif
    }
};
inline template_setup template_setup;


#endif
// library end: "lib/template.hpp"
// library begin: "lib/ds/segment_tree/lazy-segtree.hpp"
// library include: "lib/template.hpp"

namespace ryoku{
template<class acted,bool beats=false>
struct lazy_segtree{
    using info=typename acted::info;
    using tag=typename acted::tag;
    using value_type=typename acted::value_type;
    using lazy_type=typename acted::lazy_type;
    template<class T,class=void>
    struct has_commute{
        static constexpr bool value=false;
    };
    template<class T>
    struct has_commute<T,decltype((void)T::commute,void())>{
        static constexpr bool value=T::commute;
    };
    static constexpr bool commute=has_commute<tag>::value;
    int N;
    int n;
    int lg;
    vc<value_type>node;
    vc<lazy_type>lazy;
    vc<int>len;
    void build(int N_){
        assert(N_>=0);
        N=N_;
        lg=0;
        while((1<<lg)<N)lg++;
        n=1<<lg;
        node=vc<value_type>(n*2,info::id());
        lazy=vc<lazy_type>(n,tag::id());
        len=vc<int>(n*2);
        REP(i,n,n*2)len[i]=(i-n<N);
        DREP(i,n-1,1)len[i]=len[i*2]+len[i*2+1];
    }
    lazy_segtree(int N,value_type leaf=info::id()){
        build(N);
        REP(i,n,n*2)node[i]=(i-n<N?leaf:info::id());
        DREP(i,n-1,1)update(i);
    }
    lazy_segtree(int N,vc<value_type> A){
        build(N);
        A.resize(n,info::id());
        REP(i,n,n*2)node[i]=A[i-n];
        DREP(i,n-1,1)update(i);
    }
    template<class F>requires is_invocable_r_v<value_type,F&,int>
    lazy_segtree(int N,F f){
        build(N);
        REP(i,n,n*2){
            if(i-n<N)node[i]=f(i-n);
            else node[i]=info::id();
        }
        DREP(i,n-1,1)update(i);
    }
    void all_apply(int k,lazy_type x){
        assert(0<=k&&k<n*2);
        node[k]=acted::act(node[k],x,len[k]);
        if(k<n){
            lazy[k]=tag::op(lazy[k],x);
            if constexpr(beats){
                if(node[k].fail())push(k),update(k);
            }
        }
    }
    void push(int k){
        assert(0<k&&k<n);
        all_apply(k*2,lazy[k]);
        all_apply(k*2+1,lazy[k]);
        lazy[k]=tag::id();
    }
    void update(int i){
        assert(0<i&&i<n);
        node[i]=acted::act(info::op(node[i*2],node[i*2+1]),lazy[i],len[i]);
    }
    void set(int i,value_type x){
        assert(0<=i&&i<N);
        i+=n;
        for(int j=lg;j;j--)push(i>>j);
        node[i]=x;
        for(int j=1;j<=lg;j++)update(i>>j);
    }
    value_type prod(int l,int r){
        assert(0<=l&&l<=r&&r<=N);
        if(l==r)return info::id();
        if constexpr(commute){
            auto dfs=[&](auto&dfs,int k,int sl,int sr,lazy_type x)->value_type{
                if(sr<=l||r<=sl)return info::id();
                if(l<=sl&&sr<=r)return acted::act(node[k],x,len[k]);
                x=tag::op(lazy[k],x);
                int mid=(sl+sr)>>1;
                return info::op(dfs(dfs,k*2,sl,mid,x),dfs(dfs,k*2+1,mid,sr,x));
            };
            return dfs(dfs,1,0,n,tag::id());
        }
        l+=n,r+=n;
        for(int i=lg;i;i--){
            if(((l>>i)<<i)!=l)push(l>>i);
            if(((r>>i)<<i)!=r)push((r-1)>>i);
        }
        value_type sml=info::id(),smr=info::id();
        while(l<r){
            if(l&1)sml=info::op(sml,node[l++]);
            if(r&1)smr=info::op(node[--r],smr);
            l/=2,r/=2;
        }
        return info::op(sml,smr);
    }
    void apply(int l,int r,lazy_type x){
        assert(0<=l&&l<=r&&r<=N);
        if(l==r)return;
        l+=n,r+=n;
        if constexpr(!commute){
            for(int i=lg;i;i--){
                if(((l>>i)<<i)!=l)push(l>>i);
                if(((r>>i)<<i)!=r)push((r-1)>>i);
            }
        }
        int l2=l,r2=r;
        while(l2<r2){
            if(l2&1)all_apply(l2++,x);
            if(r2&1)all_apply(--r2,x);
            l2/=2,r2/=2;
        }
        for(int i=1;i<=lg;i++){
            if(((l>>i)<<i)!=l)update(l>>i);
            if(((r>>i)<<i)!=r)update((r-1)>>i);
        }
    }
    void applyat(int i,lazy_type x){
        assert(0<=i&&i<N);
        i+=n;
        if constexpr(!commute)for(int j=lg;j;j--)push(i>>j);
        all_apply(i,x);
        for(int j=1;j<=lg;j++)update(i>>j);
    }
    value_type all_prod(){
        return node[1];
    }
    template<class F>
    int max_right(int L,F f){
        assert(0<=L&&L<=N);
        if(L<N)for(int i=lg;i;i--)push((n+L)>>i);
        int l=n+L,w=1;
        value_type ansL=info::id();
        for(;L+w<=N;l>>=1,w<<=1)if(l&1){
            if(!f(info::op(ansL,node[l])))break;
            ansL=info::op(ansL,node[l++]);
            L+=w;
        }
        while(w>1){
            if(0<l&&l<n)push(l);
            l<<=1,w>>=1;
            if(L+w<=N&&f(info::op(ansL,node[l]))){
                ansL=info::op(ansL,node[l++]);
                L+=w;
            }
        }
        return L;
    }
    template<class F>
    int min_left(int R,F f){
        assert(0<=R&&R<=N);
        if(R>0)for(int i=lg;i;i--)push((n+R-1)>>i);
        int r=n+R,w=1;
        value_type ansR=info::id();
        for(;R-w>=0;r>>=1,w<<=1)if(r&1){
            if(!f(info::op(node[r-1],ansR)))break;
            ansR=info::op(node[--r],ansR);
            R-=w;
        }
        while(w>1){
            if(0<r-1&&r-1<n)push(r-1);
            r<<=1,w>>=1;
            if(R-w>=0&&f(info::op(node[r-1],ansR))){
                ansR=info::op(node[r-1],ansR);
                R-=w;
                r--;
            }
        }
        return R;
    }
};
}

#ifdef LOCAL
#include"lib/debug/formatters/ds--segment_tree--lazy-segtree.hpp"
#endif
// library end: "lib/ds/segment_tree/lazy-segtree.hpp"
// library begin: "lib/ds/act/add.hpp"
// library include: "lib/template.hpp"
// library begin: "lib/ds/monoid/min-max.hpp"
// library include: "lib/template.hpp"

namespace ryoku{
template<class T,T INF=inf<T>>
struct Min{
    using value_type=T;
    static constexpr bool commute=true;
    static value_type op(value_type a,value_type b){return min(a,b);}
    static value_type id(){return INF;}
    static value_type e(){return id();}
};
template<class T,T NEG_INF=neg_inf<T>>
struct Max{
    using value_type=T;
    static constexpr bool commute=true;
    static value_type op(value_type a,value_type b){return max(a,b);}
    static value_type id(){return NEG_INF;}
    static value_type e(){return id();}
};

}
// library end: "lib/ds/monoid/min-max.hpp"
// library begin: "lib/ds/monoid/sum-prod.hpp"
// library include: "lib/template.hpp"

namespace ryoku{
template<class T>
struct Sum{
    using value_type=T;
    static constexpr bool commute=true;
    static value_type op(value_type a,value_type b){return a+b;}
    static value_type id(){return T(0);}
    static value_type e(){return id();}
};
template<class T>
struct Prod{
    using value_type=T;
    static constexpr bool commute=true;
    static value_type op(value_type a,value_type b){return a*b;}
    static value_type id(){return T(1);}
    static value_type e(){return id();}
};

}
// library end: "lib/ds/monoid/sum-prod.hpp"

namespace ryoku{
template<class T>
struct add_min{
    using info=Min<T>;
    using tag=Sum<T>;
    using value_type=typename info::value_type;
    using lazy_type=typename tag::value_type;
    static value_type act(value_type x,lazy_type f,ll){return x+f;}
};
template<class T>
struct add_max{
    using info=Max<T>;
    using tag=Sum<T>;
    using value_type=typename info::value_type;
    using lazy_type=typename tag::value_type;
    static value_type act(value_type x,lazy_type f,ll){return x+f;}
};
template<class T>
struct add_sum{
    using info=Sum<T>;
    using tag=Sum<T>;
    using value_type=typename info::value_type;
    using lazy_type=typename tag::value_type;
    static value_type act(value_type x,lazy_type f,ll len){return x+f*len;}
};

}
// library end: "lib/ds/act/add.hpp"
// library include: "lib/ds/segment_tree/lazy-segtree.hpp"
using namespace ryoku;
void solve(){
    INT(n);
    VC(ll,a,n);
    lazy_segtree<add_min<ll>>seg(n);
    rep(i,n){
        seg.set(i,i+1-a[i]);
    }
    while(1){

    rep(i,n)dbg(seg.prod(i,i+1));
        int r=seg.max_right(0,[&](auto a){
            return a>0;
        });
        if(r==n)break;
        seg.apply(0,r,-1);
        seg.set(r,r+1);
    }
    rep(i,n)if(seg.prod(i,i+1)!=i+1)return No();
    Yes();
}
signed main(){
    int t=1;
    // cin >> t;
    while(t--)solve();
}