#The Biggest Water Problem#
The Biggest Water Problem
https://www.nowcoder.com/practice/435aa556e093463891f6da7d322140a4
#include <stdio.h>
int fun(int a)
{
int sum=0;
while(a)
{
sum+=a%10;
a/=10;
}
if(sum>9)
return fun(sum);
else
return sum;
}
int main() {
int a;
scanf("%d", &a);
printf("%d\n",fun(a));
return 0;
}
