#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 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("%1f\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("%f,%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表示没有敲）：");
	ans2 = getchar();
	
	if(ans1=='y'&&ans2=='y'||ans1=='Y'&&ans2=='Y'||ans1=='y'&&ans2=='Y'||ans1=='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')
		printf("%c是英文字母\n", x);
	else
		printf("%c是其他字符\n", x);
		
		return 0;
}

#include <stdio.h>
int main(){
	int n,sum,i,a;
	sum = 1;
	i = 1;
	a = 2;
	scanf("%d",&n);
	while(i<=n){
		sum+=a;
		a=a*2;
		i+=1;
	}
	printf("n = %d时,sum = %d\n",n,sum);
	return 0;
}