#include <bits/stdc++.h>
int main() {
  int a, b, c;
  scanf("%d %d %d", &a, &b, &c);
  if (c == 0) {
    if (a > b)
      printf("+");
    else if (b > a)
      printf("-");
    else
      printf("0");
  }
  if (c != 0) {
    if (a == b)
      printf("?");
    else if (a == (b + c))
      printf("?");
    else if (b == (a + c))
      printf("?");
    else if (a >= (b + c))
      printf("+");
    else if (b >= (a + c))
      printf("-");
    else if ((a + c) >= b && (b + c) >= a)
      printf("?");
    else
      printf("invalid");
  }
}
