#include<stdio.h>#include<string.h>#include<math.h>static int calc(int a, int b, char op, int right){if (!right)return op == '+' ? a + b : a - b;elsereturn op == '+' ? a - b : a + b;}int main(){int t;char s[256];scanf("%d", &t);while (getchar() != 'n');while (t--){gets(s);int right = 0, i, l = strlen(s), temp = 0, prev = 0, prevx = 0;char c, op = '+';for (i = 0; i < l; i++){c = s[i];if (c == '+' || c == '-'){prev = calc(prev, temp, op, right);op = c;temp = 0;}else if (c >= '0' && c <= '9'){temp = temp * 10 + c - '0';}else if (c == 'x'){if (!temp)temp = 1;prevx = calc(prevx, temp, op, right);temp = 0;}else if (c == '='){if (temp)prev = calc(prev, temp, op, right);right = 1;temp = 0;op = '+';}}if (temp)prev = calc(prev, temp, op, right);if (!prevx)puts(prev ? "IMPOSSIBLE" : "IDENTITY");elseprintf("%dn", (int) floor(prev / (double) (-prevx)));}return 0;}
