stablegradients/pie-gem5-pairs huggingface dataset:
// Slower C++ solution:
#include<iostream>

#include<cstdio>

#include<string>

using namespace std;

 int q,p,w[1000001],u[1000001],o;

 string a;

 int main()

 {

     cin>>a;//首先输入字符串

     for (int i=0;i<a.size();i++)//从0位开始循环

     {

         if (a[i]=='C') 

         {

             p++;

             u[p]=i+1;

         }//判断是否发现C这个东西，并统计其位置

         else if (a[i]=='F')

         {

            q++;

             w[q]=i+1;

         }

     }//判断是否发现F，同理 统计位置情况

     if (q>=1 && p>=1)

     {

     for (int i=1;i<=p;i++)

     {

         for (int j=1;j<=q;j++)

         {

             if (u[i]<w[j])

             {

                 o=1;

             }

         }

     }//循环，找到C是否在F的前面

     if (o==1) cout<<"Yes"<<endl;//在前面则Yes

     else cout<<"No"<<endl;//否则No   

     }

     else cout<<"No"<<endl;//不存在两个数，直接No

     //以上为全部过程，希望能理解。

 }

// Faster C++ solution for the same problem (measured speedup: 5.330697845301504x):
#include<stdio.h>

#include<string.h>

int main()

{

	int count1,count2,i,j,b;

	char a[100];

	scanf("%s",a);

	count1=0;

	count2=0;

	b=strlen(a);

	for(i=0;i<b;i++)

	{

		if(a[i]=='C') 

		{

			count1+=i;

			for(j=count1+1;j<b;j++)

			{

			    if(a[j]=='F')

			    {

			    	count2+=j;

			    }

			}

			break;

		}

	}

	if(count1<count2)printf("Yes\n");

	else printf("No\n");

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

int main(){

	string s;

	int flag=0;

	cin>>s;

	for(int i=0;i<s.length();i++){

		if(s[i]=='C')

			flag=1;

		else if(flag==1&&s[i]=='F'){

			cout<<"Yes";

			return 0;

		}

	}

	cout<<"No";

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.314027803228601x):
#include<stdio.h>

#include<string.h>

int main()

{

	int count1,count2,i,j,b;

	char a[100];

	scanf("%s",a);

	count1=0;

	count2=0;

	b=strlen(a);

	for(i=0;i<b;i++)

	{

		if(a[i]=='C') 

		{

			count1+=i;

			for(j=count1+1;j<b;j++)

			{

			    if(a[j]=='F')

			    {

			    	count2+=j;

			    }

			}

			break;

		}

	}

	if(count1<count2)printf("Yes\n");

	else printf("No\n");

}
// Slower C++ solution:
// luogu-judger-enable-o2

#include<bits/stdc++.h>

using namespace std;

int main()

{

    string a;

    cin>>a;

    if(int(a.find('C'))!=-1 and int(a.rfind('F'))!=-1 and a.find('C')<a.rfind('F'))//个人码风问题，习惯用and而不是&&

        cout<<"Yes";

    else

        cout<<"No";

}

// Faster C++ solution for the same problem (measured speedup: 5.318449098641369x):
#include<stdio.h>

#include<string.h>

int main()

{

	int count1,count2,i,j,b;

	char a[100];

	scanf("%s",a);

	count1=0;

	count2=0;

	b=strlen(a);

	for(i=0;i<b;i++)

	{

		if(a[i]=='C') 

		{

			count1+=i;

			for(j=count1+1;j<b;j++)

			{

			    if(a[j]=='F')

			    {

			    	count2+=j;

			    }

			}

			break;

		}

	}

	if(count1<count2)printf("Yes\n");

	else printf("No\n");

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

char x[10001];

bool op=0;

int main(){

	cin>>x;

	int lena=strlen(x);

	for(int i=0;i<lena;i++){

		if(x[i]=='C')op=1;

		if(op==1&&x[i]=='F'){

			cout<<"Yes";

			return 0;

		}

	}

	cout<<"No";

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.317661991408921x):
#include<stdio.h>

#include<string.h>

int main()

{

	int count1,count2,i,j,b;

	char a[100];

	scanf("%s",a);

	count1=0;

	count2=0;

	b=strlen(a);

	for(i=0;i<b;i++)

	{

		if(a[i]=='C') 

		{

			count1+=i;

			for(j=count1+1;j<b;j++)

			{

			    if(a[j]=='F')

			    {

			    	count2+=j;

			    }

			}

			break;

		}

	}

	if(count1<count2)printf("Yes\n");

	else printf("No\n");

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

int main(){

    string a;

    cin>>a;

    int cnt=0;  //用来标记

    for(int i=0;i<a.size();i++){

        if(a[i]=='C'){

            cnt=1;

        }

        if(a[i]=='F'&&cnt==1){

            cout<<"Yes";

            return 0;

        }

    }

    cout<<"No";

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.35783340670412x):
#include<stdio.h>

#include<string.h>

int main()

{

	int count1,count2,i,j,b;

	char a[100];

	scanf("%s",a);

	count1=0;

	count2=0;

	b=strlen(a);

	for(i=0;i<b;i++)

	{

		if(a[i]=='C') 

		{

			count1+=i;

			for(j=count1+1;j<b;j++)

			{

			    if(a[j]=='F')

			    {

			    	count2+=j;

			    }

			}

			break;

		}

	}

	if(count1<count2)printf("Yes\n");

	else printf("No\n");

}
// Slower C++ solution:
#include<iostream>

using namespace std;

int main(){

    string s;

	int a=0;

    cin>>s;

    for(int i=0;s[i]!='\0';++i){

    	if(s[i]=='C'){

    		a=1;

		}

		if(a==1){

			if(s[i]=='F'){

				cout<<"Yes";

				return 0;

			}

		}

	}

	cout<<"No";

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.305902995790609x):
#include<cstdio>

#include<cstring>

char a[10010]; 

bool c,f;

int main() {

    scanf("%s",a); 

    for(int i=0; i<strlen(a); i++) 

    {

        if(a[i]=='C') 

            c=true;

        if(a[i]=='F'&&c==true) 

            f=true; 

    }

    if(f==true) 

        printf("Yes\n");

    else 

        printf("No\n"); 

    return 0;

}
// Slower C++ solution:
#include<iostream>

using namespace std;

int main(){

    string s;

	int a=0;

    cin>>s;

    for(int i=0;s[i]!='\0';++i){

    	if(s[i]=='C'){

    		a=1;

		}

		if(a==1){

			if(s[i]=='F'){

				cout<<"Yes";

				return 0;

			}

		}

	}

	cout<<"No";

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.305902995790609x):
#include<cstdio>

#include<cstring>

char a[10010]; 

bool c,f;

int main() {

    scanf("%s", a);

    for(int i=0; i<strlen(a); i++) {

        if(a[i]=='C') c=true;

        if(a[i]=='F'&&c==true) f=true; 

    }

    if(f==true) printf("Yes\n"); 

    else printf("No\n");

    return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

int main()

{

	int len,i,ok=0;

	string s;

	cin>>s;

	len=s.size()-1;

	for(i=0;i<=len;i++)

	{

		if(ok==0&&s[i]=='C')

		ok=1;

		if(ok==1&&s[i]=='F')

		ok=2;

		if(ok==2)

		break;

	}

	if(ok==2)

	cout<<"Yes";

	else

	cout<<"No";

}

// Faster C++ solution for the same problem (measured speedup: 5.34895443554405x):
#include<cstdio>

#include<cstring>

char a[10010]; 

bool c,f;

int main() {

    scanf("%s", a);

    for(int i=0; i<strlen(a); i++) {

        if(a[i]=='C') c=true;

        if(a[i]=='F'&&c==true) f=true; 

    }

    if(f==true) printf("Yes\n"); 

    else printf("No\n");

    return 0;

}
// Slower C++ solution:
#include<iostream>

#include<cstring>

using namespace std;

int main(){

	string s;

	getline(cin,s);

	if(s.find("C")<s.length()){

		int k=s.find("C");

		if(s.find("F",k)<s.length()) cout<<"Yes";

		else cout<<"No";

	}

	else cout<<"No";

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.348092025928228x):
#include<cstdio>

#include<cstring>

char a[10010]; 

bool c,f;

int main() {

    scanf("%s", a);

    for(int i=0; i<strlen(a); i++) {

        if(a[i]=='C') c=true;

        if(a[i]=='F'&&c==true) f=true; 

    }

    if(f==true) printf("Yes\n"); 

    else printf("No\n");

    return 0;

}
// Slower C++ solution:
#include<iostream>

#include<cstdio>

#include<cstring>

using namespace std;

int main(){

    string s;

    cin>>s;

    for(int i=0;i<s.size();i++){

        if(s[i]=='C'){

            for(int j=i+1;j<s.size();j++){

                if(s[j]=='F'){

                    cout<<"Yes"<<endl;

                    return 0;

                }

            }

        }

    }

    cout<<"No"<<endl;

    return 0;

    

}

// Faster C++ solution for the same problem (measured speedup: 5.318236589615231x):
#include<cstdio>

#include<cstring>

char a[10010]; 

bool c,f;

int main() {

    scanf("%s", a);

    for(int i=0; i<strlen(a); i++) {

        if(a[i]=='C') c=true;

        if(a[i]=='F'&&c==true) f=true; 

    }

    if(f==true) printf("Yes\n"); 

    else printf("No\n");

    return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h> 

using namespace std;

char a[1000];

int main()

{

cin>>a;

for(int i=0;i<strlen(a);i++)

{

	if (a[i]=='C') 

	 {

	 	for(int ii=i+1;ii<strlen(a);ii++)

	 	 {

	 	 	if (a[ii]=='F') {cout<<"Yes"<<endl;return 0;}

	 	 }

	 }

}

cout<<"No"<<endl;

return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.3218180323899x):
#include<cstdio>

#include<cstring>

char a[10010]; 

bool c,f;

int main() {

    scanf("%s", a);

    for(int i=0; i<strlen(a); i++) {

        if(a[i]=='C') c=true;

        if(a[i]=='F'&&c==true) f=true; 

    }

    if(f==true) printf("Yes\n"); 

    else printf("No\n");

    return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

#include<string>

using namespace std;

int main()

{

	string n;

	int a,m;

	cin>>n;

	a=n.size();

	for(int i=0;i<a;i++)

	{

		if(n[i]=='C')

		{

			for(int k=i+1;k<=a-1;k++)

			{

				if(n[k]=='F')

				{

					cout<<"Yes"<<endl;

					return 0;

				}

			}

		}

	}

	cout<<"No"<<endl;

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.362851120759713x):
#include<cstdio>

#include<cstring>

char a[10010]; 

bool c,f;

int main() {

    scanf("%s", a);

    for(int i=0; i<strlen(a); i++) {

        if(a[i]=='C') c=true;

        if(a[i]=='F'&&c==true) f=true; 

    }

    if(f==true) printf("Yes\n"); 

    else printf("No\n");

    return 0;

}
// Slower C++ solution:
#include<iostream>

using namespace std;

int main(){

    string s;

	int a=0;

    cin>>s;

    for(int i=0;s[i]!='\0';++i){

    	if(s[i]=='C'){

    		a=1;

		}

		if(a==1){

			if(s[i]=='F'){

				cout<<"Yes";

				return 0;

			}

		}

	}

	cout<<"No";

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.355830383163841x):
#include <cstdio>

using namespace std;



int main()

{

	char ch;

	bool c=false;

	while((ch=getchar())!='\n')

		if(ch=='C')

			c=true;

		else if(ch=='F' && c)

			return printf("Yes")&0;

	printf("No");

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

int main()

{

	int len,i,ok=0;

	string s;

	cin>>s;

	len=s.size()-1;

	for(i=0;i<=len;i++)

	{

		if(ok==0&&s[i]=='C')

		ok=1;

		if(ok==1&&s[i]=='F')

		ok=2;

		if(ok==2)

		break;

	}

	if(ok==2)

	cout<<"Yes";

	else

	cout<<"No";

}

// Faster C++ solution for the same problem (measured speedup: 5.3992869275547495x):
#include <cstdio>

using namespace std;



int main()

{

	char ch;

	bool c=false;

	while((ch=getchar())!='\n')

		if(ch=='C')

			c=true;

		else if(ch=='F' && c)

			return printf("Yes")&0;

	printf("No");

	return 0;

}
// Slower C++ solution:
#include<iostream>

#include<cstring>

using namespace std;

int main(){

	string s;

	getline(cin,s);

	if(s.find("C")<s.length()){

		int k=s.find("C");

		if(s.find("F",k)<s.length()) cout<<"Yes";

		else cout<<"No";

	}

	else cout<<"No";

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.398416402852956x):
#include <cstdio>

using namespace std;



int main()

{

	char ch;

	bool c=false;

	while((ch=getchar())!='\n')

		if(ch=='C')

			c=true;

		else if(ch=='F' && c)

			return printf("Yes")&0;

	printf("No");

	return 0;

}
// Slower C++ solution:
#include<iostream>

#include<cstdio>

#include<cstring>

using namespace std;

int main(){

    string s;

    cin>>s;

    for(int i=0;i<s.size();i++){

        if(s[i]=='C'){

            for(int j=i+1;j<s.size();j++){

                if(s[j]=='F'){

                    cout<<"Yes"<<endl;

                    return 0;

                }

            }

        }

    }

    cout<<"No"<<endl;

    return 0;

    

}

// Faster C++ solution for the same problem (measured speedup: 5.368280033410353x):
#include <cstdio>

using namespace std;



int main()

{

	char ch;

	bool c=false;

	while((ch=getchar())!='\n')

		if(ch=='C')

			c=true;

		else if(ch=='F' && c)

			return printf("Yes")&0;

	printf("No");

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h> 

using namespace std;

char a[1000];

int main()

{

cin>>a;

for(int i=0;i<strlen(a);i++)

{

	if (a[i]=='C') 

	 {

	 	for(int ii=i+1;ii<strlen(a);ii++)

	 	 {

	 	 	if (a[ii]=='F') {cout<<"Yes"<<endl;return 0;}

	 	 }

	 }

}

cout<<"No"<<endl;

return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.371895176778665x):
#include <cstdio>

using namespace std;



int main()

{

	char ch;

	bool c=false;

	while((ch=getchar())!='\n')

		if(ch=='C')

			c=true;

		else if(ch=='F' && c)

			return printf("Yes")&0;

	printf("No");

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

#include<string>

using namespace std;

int main()

{

	string n;

	int a,m;

	cin>>n;

	a=n.size();

	for(int i=0;i<a;i++)

	{

		if(n[i]=='C')

		{

			for(int k=i+1;k<=a-1;k++)

			{

				if(n[k]=='F')

				{

					cout<<"Yes"<<endl;

					return 0;

				}

			}

		}

	}

	cout<<"No"<<endl;

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.413314377540616x):
#include <cstdio>

using namespace std;



int main()

{

	char ch;

	bool c=false;

	while((ch=getchar())!='\n')

		if(ch=='C')

			c=true;

		else if(ch=='F' && c)

			return printf("Yes")&0;

	printf("No");

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

int main()

{

	bool a=0;

	string b;

	cin>>b;

	for(int i=0;i<b.length();i++)

	{

		if(b[i]=='C')

			a=1;

		if(b[i]=='F'&&a)

		{

			printf("Yes\n");

			return 0;

		}

	}

	printf("No\n");

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.345667620290445x):
#include <cstdio>

using namespace std;



int main()

{

	char ch;

	bool c=false;

	while((ch=getchar())!='\n')

		if(ch=='C')

			c=true;

		else if(ch=='F' && c)

			return printf("Yes")&0;

	printf("No");

	return 0;

}
// Slower C++ solution:
#include<iostream>

using namespace std;

int main(){

    string s;

	int a=0;

    cin>>s;

    for(int i=0;s[i]!='\0';++i){

    	if(s[i]=='C'){

    		a=1;

		}

		if(a==1){

			if(s[i]=='F'){

				cout<<"Yes";

				return 0;

			}

		}

	}

	cout<<"No";

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.307425670996003x):
#include<cstdio>

#include<cstring>

char a[1000];

bool c;

int main()

{

	scanf("%s",a);

	for(int i=0;i<strlen(a);++i)

	{

		if(!c)

		{

			if(a[i]=='C')	c=1;

		}

		else

		{

			if(a[i]=='F')

			{

				printf("Yes\n");

				return 0;

			}

		}

	}

	printf("No\n");

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

int main()

{

	int len,i,ok=0;

	string s;

	cin>>s;

	len=s.size()-1;

	for(i=0;i<=len;i++)

	{

		if(ok==0&&s[i]=='C')

		ok=1;

		if(ok==1&&s[i]=='F')

		ok=2;

		if(ok==2)

		break;

	}

	if(ok==2)

	cout<<"Yes";

	else

	cout<<"No";

}

// Faster C++ solution for the same problem (measured speedup: 5.350489465547473x):
#include<cstdio>

#include<cstring>

char a[1000];

bool c;

int main()

{

	scanf("%s",a);

	for(int i=0;i<strlen(a);++i)

	{

		if(!c)

		{

			if(a[i]=='C')	c=1;

		}

		else

		{

			if(a[i]=='F')

			{

				printf("Yes\n");

				return 0;

			}

		}

	}

	printf("No\n");

	return 0;

}
// Slower C++ solution:
#include<iostream>

#include<cstring>

using namespace std;

int main(){

	string s;

	getline(cin,s);

	if(s.find("C")<s.length()){

		int k=s.find("C");

		if(s.find("F",k)<s.length()) cout<<"Yes";

		else cout<<"No";

	}

	else cout<<"No";

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.349626808439425x):
#include<cstdio>

#include<cstring>

char a[1000];

bool c;

int main()

{

	scanf("%s",a);

	for(int i=0;i<strlen(a);++i)

	{

		if(!c)

		{

			if(a[i]=='C')	c=1;

		}

		else

		{

			if(a[i]=='F')

			{

				printf("Yes\n");

				return 0;

			}

		}

	}

	printf("No\n");

	return 0;

}
// Slower C++ solution:
#include<iostream>

#include<cstdio>

#include<cstring>

using namespace std;

int main(){

    string s;

    cin>>s;

    for(int i=0;i<s.size();i++){

        if(s[i]=='C'){

            for(int j=i+1;j<s.size();j++){

                if(s[j]=='F'){

                    cout<<"Yes"<<endl;

                    return 0;

                }

            }

        }

    }

    cout<<"No"<<endl;

    return 0;

    

}

// Faster C++ solution for the same problem (measured speedup: 5.319762804285543x):
#include<cstdio>

#include<cstring>

char a[1000];

bool c;

int main()

{

	scanf("%s",a);

	for(int i=0;i<strlen(a);++i)

	{

		if(!c)

		{

			if(a[i]=='C')	c=1;

		}

		else

		{

			if(a[i]=='F')

			{

				printf("Yes\n");

				return 0;

			}

		}

	}

	printf("No\n");

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h> 

using namespace std;

char a[1000];

int main()

{

cin>>a;

for(int i=0;i<strlen(a);i++)

{

	if (a[i]=='C') 

	 {

	 	for(int ii=i+1;ii<strlen(a);ii++)

	 	 {

	 	 	if (a[ii]=='F') {cout<<"Yes"<<endl;return 0;}

	 	 }

	 }

}

cout<<"No"<<endl;

return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.323345274853996x):
#include<cstdio>

#include<cstring>

char a[1000];

bool c;

int main()

{

	scanf("%s",a);

	for(int i=0;i<strlen(a);++i)

	{

		if(!c)

		{

			if(a[i]=='C')	c=1;

		}

		else

		{

			if(a[i]=='F')

			{

				printf("Yes\n");

				return 0;

			}

		}

	}

	printf("No\n");

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

#include<string>

using namespace std;

int main()

{

	string n;

	int a,m;

	cin>>n;

	a=n.size();

	for(int i=0;i<a;i++)

	{

		if(n[i]=='C')

		{

			for(int k=i+1;k<=a-1;k++)

			{

				if(n[k]=='F')

				{

					cout<<"Yes"<<endl;

					return 0;

				}

			}

		}

	}

	cout<<"No"<<endl;

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.36439013880024x):
#include<cstdio>

#include<cstring>

char a[1000];

bool c;

int main()

{

	scanf("%s",a);

	for(int i=0;i<strlen(a);++i)

	{

		if(!c)

		{

			if(a[i]=='C')	c=1;

		}

		else

		{

			if(a[i]=='F')

			{

				printf("Yes\n");

				return 0;

			}

		}

	}

	printf("No\n");

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

int main()

{

	bool a=0;

	string b;

	cin>>b;

	for(int i=0;i<b.length();i++)

	{

		if(b[i]=='C')

			a=1;

		if(b[i]=='F'&&a)

		{

			printf("Yes\n");

			return 0;

		}

	}

	printf("No\n");

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.29735475673926x):
#include<cstdio>

#include<cstring>

char a[1000];

bool c;

int main()

{

	scanf("%s",a);

	for(int i=0;i<strlen(a);++i)

	{

		if(!c)

		{

			if(a[i]=='C')	c=1;

		}

		else

		{

			if(a[i]=='F')

			{

				printf("Yes\n");

				return 0;

			}

		}

	}

	printf("No\n");

	return 0;

}
// Slower C++ solution:
#include<iostream>

using namespace std;

int main(){

    char c;

    bool fc=0;

    while(cin>>c){

        if(c=='C'&&!fc)

            fc=1;

        if(c=='F'&&fc){

            cout<<"Yes"<<endl;

            return 0;

        }

    }

    cout<<"No"<<endl;

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.321617158543452x):
#include<cstdio>

#include<cstring>

char a[1000];

bool c;

int main()

{

	scanf("%s",a);

	for(int i=0;i<strlen(a);++i)

	{

		if(!c)

		{

			if(a[i]=='C')	c=1;

		}

		else

		{

			if(a[i]=='F')

			{

				printf("Yes\n");

				return 0;

			}

		}

	}

	printf("No\n");

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>



using namespace std;



int main()

{

    string a;

    cin >> a;

    int cnt=0;  

    for(int i=0;i<a.size();i++)

    {

        if(a[i]=='C')

            cnt=1;   

        if(a[i]=='F'&&cnt==1)

        {

            cout << "Yes";

            return 0;

        }

    }

    cout << "No";

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.351515606904488x):
#include<cstdio>

#include<cstring>

char a[1000];

bool c;

int main()

{

	scanf("%s",a);

	for(int i=0;i<strlen(a);++i)

	{

		if(!c)

		{

			if(a[i]=='C')	c=1;

		}

		else

		{

			if(a[i]=='F')

			{

				printf("Yes\n");

				return 0;

			}

		}

	}

	printf("No\n");

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

string s;

int main()

{

    cin>>s;

    int len=s.length();

    for(int i=0;i<len;i++)

    {

        if(s[i]=='C')

        {

            for(int j=i + 1;j<len;j++)

            {

                if(s[j]=='F')

                {

                    cout<<"Yes"<<endl; 

                    return 0;

                }

            }

        }

    }

    cout<<"No"<<endl;

    return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.324112502683904x):
#include<cstdio>

#include<cstring>

char a[1000];

bool c;

int main()

{

	scanf("%s",a);

	for(int i=0;i<strlen(a);++i)

	{

		if(!c)

		{

			if(a[i]=='C')	c=1;

		}

		else

		{

			if(a[i]=='F')

			{

				printf("Yes\n");

				return 0;

			}

		}

	}

	printf("No\n");

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

int main(){

	int flag=0;

	string s;

	cin>>s;

	for(int i=0;i<s.length();i++){

		if(flag==0&&s[i]=='C'){

			flag++;

			continue;

		}

		if(flag==1&&s[i]=='F'){

			cout<<"Yes";

			return 0;

		}

	}

	cout<<"No";

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 5.30791672727094x):
#include<cstdio>

#include<cstring>

char a[1000];

bool c;

int main()

{

	scanf("%s",a);

	for(int i=0;i<strlen(a);++i)

	{

		if(!c)

		{

			if(a[i]=='C')	c=1;

		}

		else

		{

			if(a[i]=='F')

			{

				printf("Yes\n");

				return 0;

			}

		}

	}

	printf("No\n");

	return 0;

}
// Slower C++ solution:
#include<iostream>

#include<cstdio>

#include<string>

using namespace std;

 int q,p,w[1000001],u[1000001],o;

 string a;

 int main()

 {

     cin>>a;

     for (int i=0;i<a.size();i++)

     {

         if (a[i]=='C') 

         {

             p++;

             u[p]=i+1;

         }

         else if (a[i]=='F')

         {

            q++;

             w[q]=i+1;

         }

     }

     if (q>=1 && p>=1)

     {

     for (int i=1;i<=p;i++)

     {

         for (int j=1;j<=q;j++)

         {

             if (u[i]<w[j])

             {

                 o=1;

             }

         }

     }

	 if (o==1) cout<<"Yes"<<endl;

     else cout<<"No"<<endl;	

     }

     else cout<<"No"<<endl;

     

     

 }

// Faster C++ solution for the same problem (measured speedup: 5.324330879244645x):
#include<cstdio>

#include<cstring>

char a[1000];

bool c;

int main()

{

	scanf("%s",a);

	for(int i=0;i<strlen(a);++i)

	{

		if(!c)

		{

			if(a[i]=='C')	c=1;

		}

		else

		{

			if(a[i]=='F')

			{

				printf("Yes\n");

				return 0;

			}

		}

	}

	printf("No\n");

	return 0;

}
// Slower C++ solution:
#include<bits/stdc++.h>

using namespace std;

char ch[110];

int n;

int main(){

	cin>>ch;

	n=strlen(ch);

	for(int i=0;i<n;i++){

		if(ch[i]=='C'){

			for(int j=i+1;j<n;j++){

				if(ch[j]=='F'){

					printf("Yes");

					return 0;

				};

			}

			printf("No");

			return 0;

		}

	}

	printf("No");

}

// Faster C++ solution for the same problem (measured speedup: 5.29961203780925x):
#include<cstdio>

#include<cstring>

char a[1000];

bool c;

int main()

{

	scanf("%s",a);

	for(int i=0;i<strlen(a);++i)

	{

		if(!c)

		{

			if(a[i]=='C')	c=1;

		}

		else

		{

			if(a[i]=='F')

			{

				printf("Yes\n");

				return 0;

			}

		}

	}

	printf("No\n");

	return 0;

}