stablegradients/pie-gem5-bysrc huggingface dataset:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;



string a;

int main(){

	cin>>a;

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

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

			for(int j=i;j<=a.length();j++){

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

					cout<<"Yes"<<endl;

					return 0;

				}

			}

		}

	}

	cout<<"No"<<endl;

	return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main()

{char a[101];

scanf("%s",a);

int l=strlen(a);

int i,j;

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

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



	for(j=i+1;j<l;j++)

{

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

		printf("Yes");

	return 0;

	}

	}



}

}



	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

string s;

vector<char>a;

int main()

{

    cin>>s;

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

    {

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

            a.push_back(s[i]);

    }

    if(a.empty()){

        cout<<"No"<<endl;

    return 0;

    }

    for(int i=0;i<a.size()-1;i++)

    {

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

        {

            cout<<"Yes"<<endl;

            return 0;

        }

    }

    cout<<"No"<<endl;

    return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main()

{char a[101];

scanf("%s",a);

int l=strlen(a);

int i,j;

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

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



	for(j=i+1;j<l;j++)

{

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

		printf("Yes");

	return 0;

	}

	}



}

}



	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

string st;

int x;

int main()

{

	cin>>st;

	for(int i=0;i<st.size()-1;i++)

	  for(int j=i+1;j<st.size();j++)if(st[i]=='C'&&st[j]=='F')x=1;

	if(x)cout<<"Yes";

	  else cout<<"No";

	return 0;

} 

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main()

{char a[101];

scanf("%s",a);

int l=strlen(a);

int i,j;

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

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



	for(j=i+1;j<l;j++)

{

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

		printf("Yes");

	return 0;

	}

	}



}

}



	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<iostream>

#include<cstdio>

#include<cstring>

using namespace std;

string s;

bool a;

int main()

{

    cin>>s;

    int l=s.length();

    for(register int i=0;i<l;++i)

    {

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

        {

            a=1;

        }

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

        {

            printf("Yes");

            return 0;

        }

    }

    printf("No");

    return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main()

{char a[101];

scanf("%s",a);

int l=strlen(a);

int i,j;

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

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



	for(j=i+1;j<l;j++)

{

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

		printf("Yes");

	return 0;

	}

	}



}

}



	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

string a;

bool y;

int main()

{

    cin>>a;

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

	{

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

		{

			cout<<"Yes"<<endl;

			return 0;

		}

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

		{

			y=1;

		}

	}

	cout<<"No"<<endl;

    return 0;

}


// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

char a[10001];

int main(){

cin>>a+1;

int M=strlen(a+1);

    for(int i=1;i<=M;i++){

        for(int j=i;j<=M;j++){

        if(a[i]=='C'&&a[j]=='F'){

            puts("Yes");

            return 0;

        }

        }

    }

    puts("No");

    return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

char s[110];

int main()

{

	int c=1000,f=-1;

	scanf("%s",&s);

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

	{

		if(s[i]=='C'&&c>i)c=i;

		if(s[i]=='F'&&f<i)f=i;

	}

	if(c<f)printf("Yes\n");

	else printf("No\n");

	return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<iostream>

#include<cstring>

using namespace std;



string a,b="CF"; 

int al,bl;



int main(){

    getline(cin,a);

    al=a.length();

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

        if(a[i]==b[bl]){ 

            bl++;

            if(bl==2)  

                break;

        }

    if(bl==2) cout<<"Yes"; 

    else cout<<"No";

    cout<<endl;

    return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

int main()

{

	string s;

	cin>>s;

	bool flag=false;

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

	{

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

		{

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

			{

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

					flag=true;

//					cout<<"gada";

				}

			}

		}

	}

	if(flag==true)

		printf("Yes");

	else printf("No");

	return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

long long i,n;

string s;

int main()

{

	cin>>s;

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

	  if (s[i]==67) n++;else

	    if (s[i]==70&&n>0) {cout<<"Yes";return 0;}

	cout<<"No"<<endl;

	return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

string s;

int l;

int main()

{

    cin>>s;

    l=s.size();

    for(register int i=0;i<l;i++)

    {

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

        {

            for(register int j=i+1;j<l;j++)

            {

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

                {

                    cout<<"Yes";

                    return 0;

                }

            }

        }

    }

    cout<<"No";

    return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

string s;

int l;

int main(){

    cin>>s;

    l=s.size();

    for(register int i=0;i<l;i++){

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

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

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

                    cout<<"Yes";

                    return 0;

                }

            }

        }

    }

    cout<<"No";

    return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

string s;

int l;

int main(){

    cin>>s;

    l=s.size();

    for( register int i=0;i<l;i++){

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

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

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

                    cout<<"Yes";

                    return 0;

                }

            }

        }

    }

    cout<<"No";

    return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include <bits/stdc++.h>

using namespace std;

char str[200];

int main()

{

	fgets(str,199,stdin);

	int l(strlen(str));

	for(register char *p=str;*p;++p)

		if(*p=='C')

			for(register char *pl=++p;*pl;pl++)

			{

				if(*pl=='F')

				{

					fwrite("Yes",3,1,stdout);

					return 0;

				}

			}

	fwrite("No",2,1,stdout);

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<iostream>

#include<string>

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";return 0;}

				}

		}

	cout<<"No";

	return 0;

	}


// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#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。

 }

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>



using namespace std;

string st;

int cs[90+5],s,P;

int main()

{

	cin>>st;

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

	{

		cs[st[i]]++;

		if(s==0)

		{

			if(st[i]==67)P=1;

			else if(P==1&&st[i]==70)P=3,s=1;

			else if(st[i]==70)P=2;

		}

		else break;

	}

	if(cs[67]>=1&&cs[70]>=1&&P==3)cout<<"Yes\n";

	else cout<<"No\n";

	

	return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

string s;

int main()

{

	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";

					return 0;

				}

			}

		}

	}

	cout<<"No";

	return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

#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;

     return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include <bits/stdc++.h>

using namespace std;

string a;

int main()

{

    cin>>a;

    bool flag1=false,flag2=false;

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

	{

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

			flag1=true;

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

			if(flag1)

			{

				cout<<"Yes"<<endl;

				exit(0);

			}

			else

				continue;

	}

	cout<<"No"<<endl;

    return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

int main(){

    string a;

    cin>>a;

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

        cout<<"Yes";

    else

        cout<<"No";

        return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
// <   .cpp> // ::

// This file is created by Bandit.

// Copyright (C) 2019 S.F.L.S , Inc.

// I don't know what this program is.

#include<bits/stdc++.h>

#define N

using namespace std;



inline int read()

{

    int x=0,f=1; char ch=getchar();

    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}

    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}

    return x*f;

}



string s;

bool f;



int main()

{

	cin>>s;

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

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

	    for (register int j=i+1;j<s.length();j++)

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

	      {

	      	 cout<<"Yes"<<endl;

	      	 return 0;

	      }

    cout<<"No"<<endl;

    return 0;

}


// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

char s[101];

int main() {

	scanf("%s",s);

	if(strchr(s,'C')!=NULL) {

		if(strchr(strchr(s,'C'),'F')!=NULL) return 0&printf("Yes");

	}

	printf("No");

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

char ch[1314520];

int main(){

	scanf("%s",ch);

	int a=0;

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

		if(ch[i]=='C'&&!a){

			a++;

			continue;

		}

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

			printf("Yes\n");

			return 0;

		}

	}

	printf("No\n");

	return 0;

} 

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main(){

	char c[5000];

	int x=0,i,j,l;

	scanf("%s",c);

	l=strlen(c);

	for(i=0;i<l;i++){

		if(x==0&&c[i]=='C'){

			x++;

		}

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

			printf("Yes");

			return 0;

		}

	}

	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<iostream>

#include<string>

#include<cstdio>

using namespace std;

string s;

bool t;

int main(){

	cin>>s;

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

		if(t && s[i]=='F'){

			puts("Yes");

			return 0;

		}

		if(s[i]=='C')t=true;

	}

	puts("No");

	return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main(){

	char c[5000];

	int x=0,i,j,l;

	scanf("%s",c);

	l=strlen(c);

	for(i=0;i<l;i++){

		if(x==0&&c[i]=='C'){

			x++;

		}

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

			printf("Yes");

			return 0;

		}

	}

	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include <cstdio>

#include <iostream>

#include <cmath>

#include <algorithm>



using namespace std;



int main(){

    char c[101];

    cin>>c;

    //

    bool cFound = false, fFound = false;

    

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

        if(c[i] == 'C' && !fFound) cFound = true;

        if(c[i] == 'F' && cFound) fFound = true;

    }

    if(cFound && fFound) cout<<"Yes";

    else cout<<"No";

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main(){

	char c[5000];

	int x=0,i,j,l;

	scanf("%s",c);

	l=strlen(c);

	for(i=0;i<l;i++){

		if(x==0&&c[i]=='C'){

			x++;

		}

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

			printf("Yes");

			return 0;

		}

	}

	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<iostream>

#include<cstdio>

#include<string>

using namespace std;

string s;

int l;

int main()

{

    cin>>s;

    l=s.size();

    for(register int i=0;i<l;i++)

    {

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

        {

            for(register int j=i+1;j<l;j++)

            {

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

                {

                    cout<<"Yes";

                    return 0;

                }

            }

        }

    }

    cout<<"No";

    return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main(){

	char c[5000];

	int x=0,i,j,l;

	scanf("%s",c);

	l=strlen(c);

	for(i=0;i<l;i++){

		if(x==0&&c[i]=='C'){

			x++;

		}

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

			printf("Yes");

			return 0;

		}

	}

	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

char cf[111];



int main(){

    scanf("%s",cf);

    bool c=false,f=false;

    int l=strlen(cf);

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

    if(c==0&&cf[i]=='C')

        c=true;

    if(c==1&&cf[i]=='F')

        f=true;}

    if(c&&f)printf("Yes");

    else printf("No");

    return 0;}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main(){

	char c[5000];

	int x=0,i,j,l;

	scanf("%s",c);

	l=strlen(c);

	for(i=0;i<l;i++){

		if(x==0&&c[i]=='C'){

			x++;

		}

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

			printf("Yes");

			return 0;

		}

	}

	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

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) cout<<"Yes"<<endl; 

    else cout<<"No\n";

    return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main(){

	char c[5000];

	int x=0,i,j,l;

	scanf("%s",c);

	l=strlen(c);

	for(i=0;i<l;i++){

		if(x==0&&c[i]=='C'){

			x++;

		}

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

			printf("Yes");

			return 0;

		}

	}

	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<iostream>

#include<cstdio>

using namespace std;

int main()

{

	int i;

	string s;

	cin>>s;

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

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

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

		if(s[j]=='F') {cout<<"Yes";return 0;}

	cout<<"No";

	return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main(){

	char c[5000];

	int x=0,i,j,l;

	scanf("%s",c);

	l=strlen(c);

	for(i=0;i<l;i++){

		if(x==0&&c[i]=='C'){

			x++;

		}

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

			printf("Yes");

			return 0;

		}

	}

	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<iostream>

#include<cstring>

using namespace std;



string a,b="CF"; 

int al,bl;



int main(){

    getline(cin,a);

    al=a.length();

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

        if(a[i]==b[bl]){ 

            bl++;

            if(bl==2)   

                break;

        }

    if(bl==2) cout<<"Yes";

    else cout<<"No";

    cout<<endl;

    return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main(){

	char c[5000];

	int x=0,i,j,l;

	scanf("%s",c);

	l=strlen(c);

	for(i=0;i<l;i++){

		if(x==0&&c[i]=='C'){

			x++;

		}

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

			printf("Yes");

			return 0;

		}

	}

	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
// ==============================

//  author: memset0

//  website: https://memset0.cn

//  date: 2018.08.06 14:06:24

// ==============================

#include <bits/stdc++.h>

#define ll long long

using namespace std;



int len;

char s[110];



int main() {

	scanf("%s", s), len = strlen(s);

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

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

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

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

					printf("Yes\n");

					return 0;

				}

	printf("No\n");

	return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main(){

	char c[5000];

	int x=0,i,j,l;

	scanf("%s",c);

	l=strlen(c);

	for(i=0;i<l;i++){

		if(x==0&&c[i]=='C'){

			x++;

		}

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

			printf("Yes");

			return 0;

		}

	}

	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

char S[110];

int main()

{

	scanf("%s",S);

	int l=strlen(S);

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

	{

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

		{

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

			{

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

				{

					printf("Yes\n");

					return 0;

				}

			}

		}

	}

	printf("No\n");

	return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main(){

	char c[5000];

	int x=0,i,j,l;

	scanf("%s",c);

	l=strlen(c);

	for(i=0;i<l;i++){

		if(x==0&&c[i]=='C'){

			x++;

		}

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

			printf("Yes");

			return 0;

		}

	}

	printf("No");

	return 0;

}

// Fastest known solution for this problem:
// Original C++ solution (slower):
#include<bits/stdc++.h>

using namespace std;

string s;

int l;

int main()

{

    cin>>s;

    l=s.size();

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

    {

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

        {

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

            {

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

                {

                    cout<<"Yes";

                    return 0;

                }

            }

        }

    }

    cout<<"No";

    return 0;

}

// Optimized solution to the same problem (faster):
#include<stdio.h>

#include<string.h>

int main(){

	char c[5000];

	int x=0,i,j,l;

	scanf("%s",c);

	l=strlen(c);

	for(i=0;i<l;i++){

		if(x==0&&c[i]=='C'){

			x++;

		}

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

			printf("Yes");

			return 0;

		}

	}

	printf("No");

	return 0;

}

// Fastest known solution for this problem: