#include <bits/stdc++.h>

using namespace std;

ifstream fin ("input.in");
ofstream fout ("output.out");

bool hasToPrint = false;
bool ifCondition = false;
bool functionEnded = false;
bool firstFunction = true;
stack <int> processes, ifStatements;
map <string, string> variables;
string printString;

void printFunction(string s) {
    hasToPrint = false;
    if (variables.find(s) != variables.end()) {
        printString += variables[s];
    }
    else {
        printString += s;
    }

}

void throwError() {
    printString = "ERROR";
    while (!processes.empty()) {
        processes.pop();
    }
}

void interpretInstruction(string instruction) {
    if (instruction == "start") {
        if (!firstFunction) {
            fout << "\n";
        }
        else {
            firstFunction = false;
        }
        processes.push(0);
        while (!ifStatements.empty()) {
            ifStatements.pop();
        }
        printString.clear();
        functionEnded = false;
    }
    if (processes.empty()) {
        return;
    }
    if (instruction == "print" && processes.top() != -1) {
        hasToPrint = true;
    }
    if (instruction == "if" && processes.top() != -1) {
        string cond;
        fin >> cond;
        string condition;
        if (variables.find(cond) != variables.end()) {
            condition = variables[cond];
        }
        else {
            condition = cond;
        }
        if (condition == "true") {
            ifCondition = true;
            processes.push(1);
        }
        else if (condition == "false") {
            ifCondition = false;
            processes.push(-1);
        }
        else {
            throwError();
        }
    }
    else if (instruction == "if") {
        processes.push(-1);
    }
    if (instruction == "else" && ifCondition == false && processes.top() != -1) {
        processes.push(1);
    }
    else if (instruction == "else") {
        processes.push(-1);
//        ifStatements.pop();
    }
    if (instruction == "var" && processes.top() != -1) {
        string name, value;
        fin >> name >> value;
        if (variables.find(name) == variables.end()) {
            variables[name] = value;
        }
        else {
            throwError();
        }
    }
    if (instruction == "set" && processes.top() != -1) {
        string name, value;
        fin >> name >> value;
        if (variables.find(name) != variables.end()) {
            if (variables.find(value) != variables.end()) {
                variables[name] = variables[value];
            }
            else {
                variables[name] = value;
            }
        }
        else {
            throwError();
        }
    }
    if (instruction == "return" && processes.top() != -1) {
        string returnvalue;
        fin >> returnvalue;
        while (processes.top() != 0) {
            processes.pop();
        }
        if (!processes.empty()) {
            processes.pop();
        }
    }
    if (instruction == "end") {
        if (!processes.empty()) {
            processes.pop();
        }
    }
}

void readInput() {

    int n;
    fin >> n;
    string instructions = " ";
    printString.clear();
    while (fin >> instructions) {
        interpretInstruction(instructions);
        if (hasToPrint && processes.top() != -1) {
            fin >> instructions;
            printFunction(instructions);
        }
        if (processes.empty() && !functionEnded) {
            functionEnded = true;
            fout << printString;
            printString.clear();
            variables.clear();
            while (!ifStatements.empty()) {
                ifStatements.pop();
            }
        }
    }

}

int main()
{
    readInput();
    return 0;
}