#include <stdio.h>
int main() {
	int num;
	
	scanf("%d", &num);
	printf("2049%04d\n", num);
	
	scanf("%d", &num);
	printf("2049%04d\n", num);
	
	scanf("%d", &num);
	printf("2049%04d\n", num);

	return 0;
}

#include <stdio.h>
int main() {
	int num,x;
	
	while(x<3)
	{
		x++;
		scanf("%d",&num);
		printf("2049%04d\n",num);
		
	}
	
	return 0;
}

#include <stdio.h>
int main() {
	int x=1234;
	float f=123.456;
	double m=123.456;
	char ch='a';
	char a[]="Hello, world!"; 
	int y=3, z=4; 
	
	printf("%d %d\n", y, z);
	printf("y=%d, z=%d\n", y,z);
	printf("%8d,%2d\n", x,x);
	printf("%f, %8f, %8.1f, %0.2f, %.2e\n",f,f,f,f,f);
	printf("%lf\n",m);
	printf("%3c\n", ch);
	printf("%s\n%15s\n%10.5s\n%2.5s\n%.3s\n",a,a,a,a,a);
	
	return 0;
}

#include <stdio.h>
int main() {
	double x,y;
	char c1,c2,c3;
	int a1,a2,a3;
	
	scanf("%d%d%d",&a1,&a2,&a3);
	printf("%d,%d,%d\n",a1,a2,a3);
	
	scanf("%c%c%c",&c1,&c2,&c3);
	printf("%c,%c,%c\n",c1,c2,c3);
	
	scanf("%lf,%lf",&x,&y);
	printf("%lf,%lf\n",x,y);

	return 0;
} 

#include <stdio.h>
int main() {
	char ans1, ans2;
	
	printf("复习了没? (输入y或Y表示复习了，输入n或N表示没复习) :  ");
	ans1 = getchar();  
	
	getchar();
	
	printf("\n动手敲代码了没? (输入y或Y表示敲了，输入n或N表示木有敲) :  ");
	ans2 = getchar();
	
	if((ans1=='y'||ans1=='Y')&&(ans2=='y'||ans2=='Y')) 
		printf("\n罗马不是一天建成的:)\n");	
	else 
		printf("\n罗马不是一天毁灭的。。。\n");

	return 0;
} 

#include <stdio.h>
int main() {
	char x;
	
	x = getchar();
	
	if(x>='0'&&x<='9') 
		printf("%c是数字字符\n", x);
	else if(x>='a'&&x<='z'||x>='A'&&x<='Z') 
		printf("%c是英文字母\n", x);
	else
		printf("%c是其它字符\n", x);
	
	
	return 0;
} 

#include<stdio.h>
int main()
{
 int a,sum,n,i;
 scanf("%d",&n);
 a=1;
 i=n;
   while(i)
 { a=a*2;
   i-=1; }
 sum=1+2*(a-1);//根据此数列a0=1,a1=2,q=2时s=a0+a1(1-q^n)/(1-q)=1+2*(2^n-1)
 printf("n=%d,sum=%d",n,sum);
}

 #include<stdio.h>
 #include<math.h>
 int main(){
    int n,sum,a,q,x;
    a=2;
    q=2;
    scanf("%d",&n);
    x=pow(2,n);
    
	sum=1+a*(1-x)/(1-2); 
	printf("n=%d,sum=%d\n",n,sum);
    return 0;
 }