#include <bits/stdc++.h>
int main() {
  char str[3][100];
  int i;
  for (i = 0; i < 3; i++) {
    scanf("%s ", &str[i][0]);
  }
  int r = 0, p = 0, s = 0;
  for (i = 0; i < 3; i++) {
    if (str[i][0] == 'r')
      r++;
    else if (str[i][0] == 'p')
      p++;
    else if (str[i][0] == 's')
      s++;
  }
  char m = 'a';
  if (r == 1 && s == 2)
    m = 'r';
  else if (s == 1 && p == 2)
    m = 's';
  else if (p == 1 && r == 2)
    m = 'p';
  if (m != 'a') {
    for (i = 0; i < 3; i++) {
      if (str[i][0] == m) break;
    }
    if (i == 0)
      printf("F");
    else if (i == 1)
      printf("M");
    else if (i == 2)
      printf("S");
  } else
    printf("?");
}
