#include<stdio.h>

int bai1(){
	int n,i=0;
	printf("Nhap n :");
    scanf("%d",&n);
    while(n > 0){
    	n/=10;
    	i++;	
    }
    printf("so luong la %d \n",i);
}
int bai2(){
	int n,i=0;
	printf("Nhap n :");
    scanf("%d",&n);
    while(n > 0){
    	if(n % 2 == 0){
    		i++;
    	}
    	n/=10;	
    }
    printf("so chan la %d \n",i);
}
int bai3(){
	int n,i,m=0;
	printf("Nhap n :");
    scanf("%d",&n);
    while(n > 0){	
    	if(i > m){
    		m = i;
    	}
    	i = n % 10;
    	n /= 10;
    		
    }
    printf("so lon nhat la la %d \n",m);
}
int bai4(){
	int n,i=0,s=1;
	printf("Nhap n :");
    scanf("%d",&n);
    while(n > 0){
    	if(n % 2 != 0){
    		i++;
    		s *= n %10;
    	}
    	n/=10;	
    }
    printf("tong so le la : %d",s);
}

int main(){
	printf("bai 1 : \n");
	bai1();
	printf("bai 2 : \n");
	bai2();
	printf("bai 3 : \n");
	bai3();
	printf("bai 4 : \n");
	bai4();
}