Some task

#include <stdio.h>
#include <math.h>

int a,i,s,k,m,p;

int main() {
    m = 0;
    p = 1;
    k = 1000;
    scanf("%i",&a);
    for (i = 1;i < 4;i++){
    k = k/10;
    s = a/k;
    m = m+s*p;
    p = p*10;
    a = a-s*k;

    }
   printf("%i\n",m);
    return 0;

}