#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,i;
    i=1;
    while(i<=3) {
    scanf("%d",&num);
    printf("2049%04d\n",num);
    i==i++;
}
    
    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.lf,%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("%f,%lf\n",x,y); 
  
  return 0;
}

 

 

#include <stdio.h>
int main(){
    char ans1,ans2;
    printf("复习了吗？(输入y或Y是复习，输入n或N是没复习):"); 
    ans1=getchar();
    
    getchar();
    printf("\n动手敲代码了没？（输入y或Y是敲了，输出n或N是没敲）：");
    ans2=getchar();
    
    if(ans1=='y'&&ans2=='y'||ans1=='Y'||ans2=='Y')
      printf("\n罗马不是一天建成的：）\n"); 
    else
      printf("\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>
#include<math.h>
int main(){
    int sum,n;
    
while(1){

    scanf("%d",&n);
    sum=1*(1-pow(2,n+1))/(1-2);
    printf("n=%d时，sum=%d\n",n,sum);
}
    return 0;
}