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

#include<cstdio>

#include<cstring>

using namespace std;

int main(){

	char a[10000];

	int b=0,c=0,d=0;

	cin>>a;

	b=strlen(a);

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

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

			c=1; 

		}

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

			d=1;

		}

	}

	if(c>0&&d>0) cout<<"Yes"<<endl;

	else cout<<"No"<<endl;

	return 0;

}

// Optimized solution to the same problem (faster):
#include<cstdio>

#include<cstring>

char a[105];

int main(){

	scanf("%s",a);

	for(int i=0;i<=strlen(a)-1;i++){

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

			for(int j=strlen(a)-1;j>i;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 a;

int main()

{

	cin.tie(0);

	cout.tie(0);

	cin>>a;

	int len=a.size();

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

	{

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

		{

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

			{

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

				{

					printf("Yes");

					return 0;

				}

			}

			break;

		}

	}

	printf("No");

	return 0;

} 

// Optimized solution to the same problem (faster):
#include<cstdio>

#include<cstring>

char a[105];

int main(){

	scanf("%s",a);

	for(int i=0;i<=strlen(a)-1;i++){

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

			for(int j=strlen(a)-1;j>i;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<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<cstdio>

#include<cstring>

char a[105];

int main(){

	scanf("%s",a);

	for(int i=0;i<=strlen(a)-1;i++){

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

			for(int j=strlen(a)-1;j>i;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;

int main()

{

	string a1;

	cin>>a1;

	int a=a1.length();

	//reverse(a1,a1+a);

	if(a1.find('C')==a1.npos|a1.find('F')==a1.npos)

		cout<<"No";

	else if(a1.find_first_of('C')<a1.find_last_of('F') )cout<<"Yes";

	else cout<<"No";

}

// Optimized solution to the same problem (faster):
#include<cstdio>

#include<cstring>

char a[105];

int main(){

	scanf("%s",a);

	for(int i=0;i<=strlen(a)-1;i++){

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

			for(int j=strlen(a)-1;j>i;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<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>

char ch[10000010];

bool flag;

int main ( )

{

    scanf("%s",ch);

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

    {

        if(ch[i]=='C')flag=1;

        if(ch[i]=='F'&&flag)

            return puts("Yes")&0;

    }

    puts("No");

    return 0;

}

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

#include <cstdio>

#include <string>



using namespace std;



int main()

{

	string s;

	cin >> s;

	int i, s_l = s.length();

	int tot = 0;

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

	{

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

			tot++;

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

			tot++;

	}

	if (tot == 2)

		printf("Yes");

	else

		printf("No");

	return 0;

}

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

#include<string.h>

char ch[10000010];

bool flag;

int main ( )

{

    scanf("%s",ch);

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

    {

        if(ch[i]=='C')flag=1;

        if(ch[i]=='F'&&flag)

            return puts("Yes")&0;

    }

    puts("No");

    return 0;

}

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

using namespace std;

char c[10001];

int a=999999,b;

int main()

{

    cin>>c;

    for(int i=0;i<=105;i++)

    {

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

        {

            a=i; break;

        }

    }

    for(int i=0;i<=105;i++)

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

      b=i;

    if(a<b)

     printf("Yes\n");

    else

     printf("No\n");

     return 0;

}

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

#include<string.h>

char ch[10000010];

bool flag;

int main ( )

{

    scanf("%s",ch);

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

    {

        if(ch[i]=='C')flag=1;

        if(ch[i]=='F'&&flag)

            return puts("Yes")&0;

    }

    puts("No");

    return 0;

}

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

#include <cstdio>

#include <cstring>



using namespace std;



const int kmaxN = 10000 + 10;

char c[kmaxN];

int mark1,mark2;



int main()

{

	cin >> c;

	int l = strlen(c);

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

	{

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

			mark1 = 1;

		if(mark1 == 1 && c[i] == 'F')

		{

			mark2 = 1;

			break;

		}

	}

	if(mark1 == 1 && mark2 == 1)

		cout << "Yes";

	else

		cout << "No";

	return 0;

}

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

#include<string.h>

char ch[10000010];

bool flag;

int main ( )

{

    scanf("%s",ch);

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

    {

        if(ch[i]=='C')flag=1;

        if(ch[i]=='F'&&flag)

            return puts("Yes")&0;

    }

    puts("No");

    return 0;

}

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

#include <iostream>

#include <cstdio>

#include <string>

using namespace std;

int main()

{

    string word;

    cin>>word;

    int l=word.size(),cnt=0;

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

    {

        if(word[i]=='C'&&!cnt)  cnt++;

        if(word[i]=='F'&&cnt)  

        {

            cnt++;break;

        }

    }

    if(cnt==2)  printf("Yes\n");

    else  printf("No\n");

    return 0;

}

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

#include<string.h>

char ch[10000010];

bool flag;

int main ( )

{

    scanf("%s",ch);

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

    {

        if(ch[i]=='C')flag=1;

        if(ch[i]=='F'&&flag)

            return puts("Yes")&0;

    }

    puts("No");

    return 0;

}

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

using namespace std;

int main(){

	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);

	register string st;

	register bool c=false,f=false;

	cin>>st;

	int len=st.length();

	register char ch[len];

	for(int i=0;i<len;i++)ch[i]=st[i];

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

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

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

		if(c&&f){

			cout<<"Yes\n";

			return 0;

		}

	}

	cout<<"No\n";

	return 0;

}

// Optimized solution to the same problem (faster):
#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");

}

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

#include<string>

using namespace std;

string s;

int i,flagc=0,flagf=0;

int main()

{

    cin>>s;

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

    {

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

            flagc=1;

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

            flagf=1;

    }

    if(flagc&&flagf)

        cout<<"Yes"<<endl;

    else

        cout<<"No"<<endl;

    return 0;

}

// Optimized solution to the same problem (faster):
#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");

}

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

#include <cstdio>

#include <cstring>

using namespace std;

int main()

{

	string s;

	int flag1=0;

	int flag2=0;

	cin>>s;

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

	{

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

			flag1=1;

		if(s[i]=='F'&&flag1==1)

			flag2=1;

	}

	if(flag1==1&&flag2==1)

		cout<<"Yes"<<endl;

	else

		cout<<"No"<<endl;

	return 0;

}

// Optimized solution to the same problem (faster):
#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");

}

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

using namespace std;

string s;

int main()

{

	cin>>s;

	int len=s.size();

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

	{

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

		{

			for(int j=i;j<=len;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>

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");

}

// 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()

{

	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");

}

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

using namespace std;

char a[500];

int main()

{

	cin>>a;

	int ls=strlen(a);

	for(int i=0;i<ls-1;i++)

	{

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

		{

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

{

	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");

}

// 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()

{

	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");

}

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

#include<cstring>

using namespace std;

char b[115];

int main()

{

	int l=0;

	cin>>b;int len=strlen(b);

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

	{

		char a=b[i];

		if(a=='C'&&l==0) l=1;

		if(l==1&&a=='F') l=2;

	}

	if(l==2) cout<<"Yes"<<endl;

	else cout<<"No"<<endl;

	return 0;

}

// Optimized solution to the same problem (faster):
#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");

}

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

using namespace std;

string a;

int b;

int main(){

	ios::sync_with_stdio(false);

	cin>>a;

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

		if(a[i]=='C'&&b==0){

			b=1;

			//cout<<i<<endl;

		}

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

			b=2;

			//cout<<i<<endl; 

		}

	}

	if(b==2) cout<<"Yes"<<endl;

	else cout<<"No"<<endl;

	return 0;

} 

// Optimized solution to the same problem (faster):
#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");

}

// 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>

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");

}

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

}

// Optimized solution to the same problem (faster):
#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");

}

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

}

// Optimized solution to the same problem (faster):
#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");

}

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

}

// Optimized solution to the same problem (faster):
#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");

}

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

}

// Optimized solution to the same problem (faster):
#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");

}

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

}

// Optimized solution to the same problem (faster):
#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;

}

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

}

// Optimized solution to the same problem (faster):
#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;

}

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

}

// Optimized solution to the same problem (faster):
#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;

}

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

    

}

// Optimized solution to the same problem (faster):
#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;

}

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

}

// Optimized solution to the same problem (faster):
#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;

}

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

}

// Optimized solution to the same problem (faster):
#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;

}

// Fastest known solution for this problem: