#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

int main() {
  assert(sizeof(unsigned long) == 4);
  printf("%ul\n", (unsigned long)strtol("4294967295", NULL, 10));
  printf("%ul\n", (unsigned long)strtoll("4294967295", NULL, 10));
  return 0;
}

2147483647l
4294967295l