PRoblem Description

Input

Output

Example Input

22424
Example Output
2#include<stdio.h>#include<string.h>void main(){    char str[1001];    gets(str);    int flag=0,i;    for(i=0;i<strlen(str);i++)        if(str[i]=='2'&&str[i+1]=='4')            flag++;        printf("%d/n",flag);}